5 ideas
21558 | 'Predicative' norms are those which define a class [Russell] |
Full Idea: Norms (containing one variable) which do not define classes I propose to call 'non-predicative'; those which do define classes I shall call 'predicative'. | |
From: Bertrand Russell (Difficulties of Transfinite Numbers and Types [1905], p.141) |
21559 | We need rules for deciding which norms are predicative (unless none of them are) [Russell] |
Full Idea: We need rules for deciding what norms are predicative and what are not, unless we adopt the view (which has much to recommend it) that no norms are predicative. ...[146] A predative propositional function is one which determines a class. | |
From: Bertrand Russell (Difficulties of Transfinite Numbers and Types [1905], p.141) | |
A reaction: He is referring to his 'no class' theory, which he favoured at that time. |
7946 | The memory criterion has a problem when one thing branches into two things [Williams,B, by Macdonald,C] |
Full Idea: The memory criterion for personal identity permits 'branching' (where two things can later meet the criteria of persistence of a single earlier thing), which presents it with serious problems. | |
From: report of Bernard Williams (Personal Identity and Individuation [1956]) by Cynthia Macdonald - Varieties of Things Ch.4 | |
A reaction: Of course, any notion of personal identity would have serious problem if people could branch into two, like fissioning amoeba. If that happened, we probably wouldn't have had a strong notion of personal identity in the first place. See Parfit. |
1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
Full Idea: Archelaus was the first person to say that the universe is boundless. | |
From: report of Archelaus (fragments/reports [c.450 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Ar.3 |
5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |
Full Idea: Archelaus wrote that life on Earth began in a primeval slime. | |
From: report of Archelaus (fragments/reports [c.450 BCE]) by Malcolm Schofield - Archelaus | |
A reaction: This sounds like a fairly clearcut assertion of the production of life by evolution. Darwin's contribution was to propose the mechanism for achieving it. We should honour the name of Archelaus for this idea. |