18 ideas
| 1542 | Diogenes of Apollonia was the last natural scientist [Diogenes of Apollonia, by Simplicius] |
| 13338 | '"It is snowing" is true if and only if it is snowing' is a partial definition of the concept of truth [Tarski] |
| 13337 | A language: primitive terms, then definition rules, then sentences, then axioms, and finally inference rules [Tarski] |
| 13335 | Semantics is the concepts of connections of language to reality, such as denotation, definition and truth [Tarski] |
| 13336 | A language containing its own semantics is inconsistent - but we can use a second language [Tarski] |
| 13339 | A sentence is satisfied when we can assert the sentence when the variables are assigned [Tarski] |
| 13340 | Satisfaction is the easiest semantical concept to define, and the others will reduce to it [Tarski] |
| 13341 | Using the definition of truth, we can prove theories consistent within sound logics [Tarski] |
| 489 | Each thing must be in some way unique [Diogenes of Apollonia] |
| 483 | Start a thesis with something undisputable [Diogenes of Apollonia] |
| 1544 | Perception must be an internal matter, because we can fail to perceive when we are preoccupied [Diogenes of Apollonia, by Theophrastus] |
| 5880 | Xenocrates held that the soul had no form or substance, but was number [Xenocrates, by Cicero] |
| 24042 | The older Diogenes said the soul is air, made of the smallest particles [Diogenes of Apollonia] |
| 5995 | Diogenes of Apollonia offered the first teleological account of cosmology [Diogenes of Apollonia, by Robinson,TM] |
| 488 | Air is divine, because it is in and around everything, and arranges everything [Diogenes of Apollonia] |
| 484 | Everything is ultimately a variation of one underlying thing [Diogenes of Apollonia] |
| 486 | Plants and animals can only come into existence if something fixes their species [Diogenes of Apollonia] |
| 485 | Things must retain their essential nature during change, or mixing would be impossible [Diogenes of Apollonia] |