10 ideas
13432 | The essence of a circle is the equality of its radii [Leibniz] |
Full Idea: The essence of a circle consists in the equality of all lines drawn from its centre to its circumference. | |
From: Gottfried Leibniz (Letters to Thomasius [1669], 1669) | |
A reaction: Compare Locke in Idea 13431 and Spinoza in Idea 13073 on the essence of geometrical figures. A key question is whether the essence is in the simplest definition, or in a complex and wide-ranging account, e.g. including conic sections for circles. |
5673 | If we have a pain, we are strongly aware of the bodily self [Cassam] |
Full Idea: Since sensations such as pain generally present themselves as in some part of one's body, the bodily self seems to be anything but elusive in sensory awareness. | |
From: Quassim Cassam (Introduction to 'Self-Knowledge' [1994], §I) | |
A reaction: This strikes me as a really good observation. Whenever we do Hume's experiment in introspection, we tend to examine either pure sense experiences or abstract ideas. If we introspect a pain, we actually find the body at the centre of activity. |
5670 | Knowledge of thoughts covers both their existence and their contents [Cassam] |
Full Idea: Our knowledge of our thoughts includes both our knowledge that we think and our knowledge of the contents of our thought. | |
From: Quassim Cassam (Introduction to 'Self-Knowledge' [1994], §I) | |
A reaction: This seems like a simple, self-evident and true distinction. We might question the first part, though. Knowledge involves the contents, but the fact that we think may be an inference from the contents, or even a fictional abstraction. Contents alone? |
5671 | Outer senses are as important as introspection in the acquisition of self-knowledge [Cassam] |
Full Idea: It would be quite legitimate to claim that the outer senses are at least as important as introspection in the acquisition of self-knowledge. | |
From: Quassim Cassam (Introduction to 'Self-Knowledge' [1994], §I) | |
A reaction: It is interesting to speculate about the extent to which a 'mind in a void' could have a personal identity. Experiences tend to be 'mine' because of my body, which has a history and a space-time location. But this doesn't make identity entirely cultural. |
5672 | Is there a mode of self-awareness that isn't perception, and could it give self-knowledge? [Cassam] |
Full Idea: The key questions are: can one be introspectively aware of oneself other than through an inner sense, and, if there is a non-perceptual mode of introspective self-awareness, can it be the ground or basis of one's self-knowledge? | |
From: Quassim Cassam (Introduction to 'Self-Knowledge' [1994], §I) | |
A reaction: Perception would involve a controlled attempt to experience a separate object. The other mode would presumably be more direct. The question boils down to 'is there an object which introspection can attempt to perceive?' Good question. |
5675 | Neither self-consciousness nor self-reference require self-knowledge [Cassam] |
Full Idea: According to Kant, self-consciousness does not require self-knowledge, and it also appears that self-reference does not require self-knowledge. | |
From: Quassim Cassam (Introduction to 'Self-Knowledge' [1994], §II) | |
A reaction: Kant's point is that knowledge requires a stage of conceptualisation, which simple self-consciousness might not involve. The second point is that self-reference require no knowledge because error is impossible. Two nice points, and useful distinctions. |
5674 | We can't introspect ourselves as objects, because that would involve possible error [Cassam] |
Full Idea: One can identify an object in a mirror as oneself, but that brings with it the possibility of misidentification, so since introspective awareness statements are immune to error, one is not introspectively aware of oneself as an object. | |
From: Quassim Cassam (Introduction to 'Self-Knowledge' [1994], §I) | |
A reaction: As a pure argument this looks weak. There could be two sorts of knowledge of objects, one admitting possible error, the other not. Introspecting pain appears to be awareness of oneself as an object. Planning my future needs my body. |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
12696 | Bodies are recreated in motion, and don't exist in intervening instants [Leibniz] |
Full Idea: I have demonstrated that whatever moves is continuously created and that bodies are nothing at any time between the instants in motion. | |
From: Gottfried Leibniz (Letters to Thomasius [1669], 1669.04), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 1 | |
A reaction: Leibniz is a little over-confident about what he has 'demonstrated', but I think (from this remark) that he would not have been displeased with quantum theory, and the notion of a 'quantum leap' and a 'Planck time'. A 'conatus' is a 'smallest motion'. |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |