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11. Knowledge Aims / B. Certain Knowledge / 1. Certainty

[possibility or necessity of certainty in knowledge]

34 ideas
How can you be certain about aspects of the world if they aren't constant? [Plato]
     Full Idea: Could we attribute certainty to studying aspects of the world, such as how it arose, or acts, or is acted upon, when none of them ever was or will be constant? Of course not.
     From: Plato (Philebus [c.353 BCE], 59b)
Knowledge proceeds from principles, so it is hard to know if we know [Aristotle]
     Full Idea: It is difficult to know whether you know something or not. For it is difficult to know whether or not our knowledge of something proceeds from its principles - and this is what it is to know something.
     From: Aristotle (Posterior Analytics [c.327 BCE], 76a25)
The conclusions of speculative reason about necessities are certain [Aquinas]
     Full Idea: Since the speculative reason is concerned chiefly with necessary things, which cannot be otherwise than they are, its proper conclusions, like the universal principles, contain the truth without fail.
     From: Thomas Aquinas (Summa Theologicae [1265], I-II Q94 4)
     A reaction: This seems over-confident, and to confuse the facts with our knowledge of the facts. Simple arithmetic may seem certain, but long and intricate proofs are always a little uncertain.
Certainty comes from the self-evident, from induction, and from self-awareness [Duns Scotus, by Dumont]
     Full Idea: Duns Scotus grounded certitude in the knowledge of self-evident propositions, induction, and awareness of our own state.
     From: report of John Duns Scotus (works [1301]) by Stephen D. Dumont - Duns Scotus p.206
     A reaction: Induction looks like the weak link here.
Knowledge is certain cognition of something that is true [William of Ockham]
     Full Idea: Knowledge is certain cognition of something that is true.
     From: William of Ockham (Expositio super viii libros [1340], Prologue)
     A reaction: This view has problems. William is not facing up to the sceptical questions which can shake any degree of certainty, and also that someone who lacked self-confidence might know many things while always feeling uncertain about them. 'Cognition' must go!
If we accept mere probabilities as true we undermine our existing knowledge [Descartes]
     Full Idea: It is better never to study than to be unable to distinguish the true from the false, and be obliged to accept as certain what is doubtful. One risks losing the knowledge one already has. Hence we reject all those knowledges which are only probable.
     From: René Descartes (Rules for the Direction of the Mind [1628], 02)
     A reaction: This is usually seen nowadays (and I agree) that this is a false dichotomy. Knowledge can't be all-or-nothing. We should accept probabilities as probable, not as knowledge. Probability became a science after Descartes.
In pursuing truth, anything less certain than mathematics is a waste of time [Descartes]
     Full Idea: In our search for the direct road towards truth we should busy ourselves with no object about which we cannot attain a certitude equal to that of the demonstrations of Arithmetic and Geometry.
     From: René Descartes (Rules for the Direction of the Mind [1628], Rule II), quoted by Alain Badiou - Mathematics and Philosophy: grand and little p.8
     A reaction: A beautiful statement of the way in which rationalist philosophy was founded on the model of mathematics (esp. Euclid), with all its concomitant problems. The most important concept of the last hundred years may well be fallibilist rationalism.
In morals Descartes accepts the conventional, but rejects it in epistemology [Roochnik on Descartes]
     Full Idea: Descartes' procedure for treating values (accepting normal conventions when faced with uncertainty) is the exact antithesis of that used to attain knowledge.
     From: comment on René Descartes (A Discourse on Method [1637], §3.23) by David Roochnik - The Tragedy of Reason p.73
Descartes tried to model reason on maths instead of 'logos' [Roochnik on Descartes]
     Full Idea: Descartes rejects logos because it does not achieve the certainty he craves. He replaces it with his own model of rationality, one modelled essentially on mathematics.
     From: comment on René Descartes (Meditations [1641], §1) by David Roochnik - The Tragedy of Reason p.76
Labelling slightly doubtful things as false is irrational [Roochnik on Descartes]
     Full Idea: To declare that which is the least bit dubious as absolutely false is to declare war on logos.
     From: comment on René Descartes (Meditations [1641], §1.17) by David Roochnik - The Tragedy of Reason p.72
Maybe there is only one certain fact, which is that nothing is certain [Descartes]
     Full Idea: If I suppose that everything I see is false. Nothing I remember actually existed. I have no senses, and body, shape, extension, movement and place are all chimeras. What then is true? Perhaps just the single fact that nothing is certain.
     From: René Descartes (Meditations [1641], §2.24)
Understanding, not the senses, gives certainty [Descartes]
     Full Idea: Certainty is not in the sense but in the understanding alone, when it has evident perceptions.
     From: René Descartes (Preface to 'Principles of Philosophy' [1647], p.177)
True ideas intrinsically involve the highest degree of certainty [Spinoza]
     Full Idea: No one who has a true idea is ignorant that a true idea involves the highest certitude; to have a true idea signifying just this, to know a thing perfectly or as well as possible.
     From: Baruch de Spinoza (The Ethics [1675], II Pr 43)
     A reaction: This wildly optimistic view is found in rationalists of the period. Rationalism only becomes tolerable if fallibilism is added to it. See Bonjour.
You only know you are certain of something when you actually are certain of it [Spinoza]
     Full Idea: Who can know that he understands some thing unless he first understands it? That is, who can know that he is certain about some thing unless he is first certain about it?
     From: Baruch de Spinoza (The Ethics [1675], II Pr 43S)
     A reaction: This seems to beg the question, which concerns how you get to the state of full understanding or certainty in the first place. Spinoza thinks only certainty counts as knowledge, which seems to derive from Descartes. I prefer Peirce.
A man who assents without doubt to a falsehood is not certain, but lacks a cause to make him waver [Spinoza]
     Full Idea: When we say that a man assents to what is false and does not doubt it, we do not say that he is certain, but merely that he does not doubt, that is, that he assents to what is false, because there are no causes sufficient to make his imagination waver.
     From: Baruch de Spinoza (The Ethics [1675], II Pr 49)
     A reaction: This is a seventeenth century rationalist desperate to say that the reason can deliver certainty, in the face of idiots who are totally certain about astrology, fairies and what not. Vain hope, I'm afraid. Fallibilist rationalism is required.
The greatest certainty is knowing our own ideas, and that two ideas are different [Locke]
     Full Idea: A man cannot conceive himself capable of a greater certainty, than to know that any idea in his mind is such as he perceives it to be; and that two ideas wherein he perceives a difference, are different, and not precisely the same.
     From: John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 4.02.01)
     A reaction: That leaves open the question of what you know when you know your ideas. Do you fully know the contents? The contingent truths expressed by some of them? Or just their meanings?
General certainty is only found in ideas [Locke]
     Full Idea: General certainty is never to be found but in our ideas.
     From: John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 4.06.16)
     A reaction: This is a fairly standard empirical view of such things. The obvious opposition to it might be Moore's 'hand' example (Idea 6349), if we ask, which is more certain, this hand I hold up, or this complex proof in mathematics?
If it is knowledge, it is certain; if it isn't certain, it isn't knowledge [Locke]
     Full Idea: What reaches to knowledge, I think may be called certainty; and what comes short of certainty, I think cannot be knowledge.
     From: John Locke (Letters to Edward Stillingfleet [1695], Letter 2), quoted by Simon Blackburn - Quasi-Realism no Fictionalism
     A reaction: I much prefer that fallibilist approach offered by the pragmatists. Knowledge is well-supported belief which seems (and is agreed) to be true, but there is a small shadow of doubt hanging over all of it.
Certainty is where practical doubt is insane, or at least blameworthy [Leibniz]
     Full Idea: Certainty might be knowledge of a truth such that to doubt it in a practical way would be insane; and sometimes it is taken more broadly, to cover cases where doubt would be very blameworthy.
     From: Gottfried Leibniz (New Essays on Human Understanding [1704], 4.11)
     A reaction: The normative aspect of the second half of this touches on a trend in recent epistemology. You have rights to believe, and duties to believe, and virtues for the justifying process. I prefer more neutral, value-free epistemology.
In absolute knowing, the gap between object and oneself closes, producing certainty [Hegel]
     Full Idea: In absolute knowing ...the separation of the object from the certainty of oneself is completely eliminated: truth is now equated with certainty and this certainty with truth.
     From: Georg W.F.Hegel (Science of Logic [1816], p.49), quoted by Stephen Houlgate - An Introduction to Hegel 03 'Absolute'
     A reaction: I don't understand this, but I note it because Hegel is evidently not a fallibilist about knowledge. I take this idea to be Descartes' 'clear and distinct ideas', wearing a grand rhetorical uniform.
Being certain presumes that there are absolute truths, and means of arriving at them [Nietzsche]
     Full Idea: Conviction is the belief that in some point of knowledge one possesses absolute truth. Such a belief presumes, then, that absolute truths exists; likewise, that the perfect methods for arriving at them have been found.
     From: Friedrich Nietzsche (Human, All Too Human [1878], 630)
A note for asses: What convinces is not necessarily true - it is merely convincing [Nietzsche]
     Full Idea: What convinces is not necessarily true - it is merely convincing (a note for asses).
     From: Friedrich Nietzsche (The Will to Power (notebooks) [1888], §017)
     A reaction: I hope I am not such an ass that I need Nietzsche to explain this, as I have always thought it true. Many good modern epistemologists seem to me guilty of this error, though. Pragmatists, riff-raff like that…
The quest for certainty aims for peace, and avoidance of the stress of action [Dewey]
     Full Idea: The quest for certainty is a quest for a peace which is assured, an object which is unqualified by risk and the shadow of fear which action costs.
     From: John Dewey (The Later Works (17 vols, ed Boydston) [1930], 4:7), quoted by David Hildebrand - Dewey 2 'Intro'
     A reaction: This is a characteristic pragmatist account. I think Dewey and Peirce offer us the correct attitude to certainty. It is just not available to us, and can only be a delusion. That doesn't mean we don't know anything, however!
We want certainty in order achieve secure results for action [Dewey]
     Full Idea: The ultimate ground of the quest for cognitive certainty is the need for security in the results for action.
     From: John Dewey (The Quest for Certainty [1929], p.39), quoted by Erik J. Olsson - Against Coherence 10.5
     A reaction: Just what a pragmatist should say. This may be true within an evolutionary account of human nature, but seems unlikely when doing a sudoku. The 'ground' of the quest may not be the same as its 'source'.
My theory aims at the certitude of mathematical methods [Hilbert]
     Full Idea: The goal of my theory is to establish once and for all the certitude of mathematical methods.
     From: David Hilbert (On the Infinite [1925], p.184), quoted by James Robert Brown - Philosophy of Mathematics Ch.5
     A reaction: This dream is famous for being shattered by Gödel's Incompleteness Theorem a mere six years later. Neverless there seem to be more limited certainties which are accepted in mathematics. The certainty of the whole of arithmetic is beyond us.
Knowledge is superior to opinion because it is certain [Ross]
     Full Idea: Knowledge is superior in value to opinion because it has certainty or complete absence of doubt.
     From: W. David Ross (The Right and the Good [1930], §VI)
     A reaction: This strikes me as a classic blunder, dating back to Descartes, which I think of as 'setting the bar too high'. It leads without fail to scepticism, because certainty is simply impossible for human beings. I am a committed fallibilist about knowledge.
Convictions are failures to study anything thoroughly [Cioran]
     Full Idea: We have convictions only if we have studied nothing thoroughly.
     From: E.M. Cioran (The Trouble with Being Born [1973], 08)
     A reaction: Excellent! I cannot imagine studying anything at all in great depth without it resulting in a dwindling expectation of full understanding. Philosophy in spades, but also probably any topic in history.
Opinions are fine, but having convictions means something has gone wrong [Cioran]
     Full Idea: To have opinions is inevitable, is natural; to have convictions is less so. Each time I meet someone who has convictions, I wonder what intellectual vice, what flaw has caused him to acquire such a thing.
     From: E.M. Cioran (The Trouble with Being Born [1973], 12)
     A reaction: 'The best lack all conviction/ While the worst are full of passionate intensity' (Yeats). I agree with this. Convictions are so often accompanied by anger.
Only tautologies can be certain; other propositions can only be probable [Ayer]
     Full Idea: No proposition, other than a tautology, can possibly be anything more than a probable hypothesis.
     From: A.J. Ayer (Language,Truth and Logic [1936], Ch.1)
     A reaction: A nice clear empiricist rejection of all attempts to assert necessary truths about nature. This also seems to be a rejection of empiricist foundationalism. A problem case seems to be introspective observations, which seem irrefutable and obvious.
A pupil who lacks confidence may clearly know something but not be certain of it [Dancy,J]
     Full Idea: Why isn't certainty required for knowledge? Because we are often prepared to allow that someone does in fact have knowledge when the person is so uncertain they would not claim knowledge for themselves (the 'diffident schoolboy').
     From: Jonathan Dancy (Intro to Contemporary Epistemology [1985], 2.1)
Propositions make error possible, so basic experiential knowledge is impossible [Williams,M]
     Full Idea: Propositional content is inseparable from possible error. Therefore no judgement, however modest, is indubitable. So if basic experiential knowledge has to be indubitable, there is no such knowledge.
     From: Michael Williams (Problems of Knowledge [2001], Ch. 8)
We can make certain of what we know, so knowing does not entail certainty [Audi,R]
     Full Idea: The possibility of making certain of what we already know suggests that knowing a proposition does not entail its being certain.
     From: Robert Audi (Epistemology: contemporary introduction [1998], VIII p.220)
Most people now agree that our reasoning proceeds defeasibly, rather than deductively [Pollock/Cruz]
     Full Idea: One of the most important modern advances in epistemology was the recognition of defeasible reasons; it is now generally acknowledged that most of our reasoning proceeds defeasibly rather than deductively.
     From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §1.2)
     A reaction: I agree totally. This is why fallibilism is clearly a correct position in epistemology (e.g. Ideas 2736 and 2755). Deduction is not the only grounds given for certainty - there are rationalist foundations (Descartes) and empiricist foundations (Moore).
To believe maximum truths, believe everything; to have infallible beliefs, believe nothing [Pollock/Cruz]
     Full Idea: If we want an agent to believe as many truths as possible, this could be achieved by simply believing everything; if we want an agent to have only true beliefs, this could be achieved by believing nothing.
     From: J Pollock / J Cruz (Contemporary theories of Knowledge (2nd) [1999], §6.6)
     A reaction: I like this. It highlights the pragmatic need for a middle road, in which a core set of beliefs are going to be approved of as 'knowledge', so that we can get on with life. This has to be a social matter, and needs flexibility of Fallibilism.