more from this thinker | more from this text
Full Idea
'Tree' is not a sortal concept under which directions fall since we cannot adequately explain the truth-conditions of any identity statement involving a pair of tree-denoting singular terms by appealing to facts to do with parallelism between lines.
Gist of Idea
Entities fall under a sortal concept if they can be used to explain identity statements concerning them
Source
Crispin Wright (Frege's Concept of Numbers as Objects [1983], 3.xiv)
Book Ref
Wright,Crispin: 'Frege's Conception of Numbers' [Scots Philosophical Monographs 1983], p.114
A Reaction
The idea seems to be that these two fall under 'hedgehog', because that is a respect in which they are identical. I like to notion of explanation as a part of this.
| 8735 | Kant implies that concepts have analysable parts [Kant, by Shapiro] |
| 14793 | The definition of a concept is just its experimental implications [Peirce] |
| 21214 | We clarify concepts (e.g. numbers) by determining their psychological origin [Husserl, by Velarde-Mayol] |
| 12621 | Definable concepts have constituents, which are necessary, individuate them, and demonstrate possession [Fodor] |
| 13890 | Entities fall under a sortal concept if they can be used to explain identity statements concerning them [Wright,C] |
| 12584 | An analysis of concepts must link them to something unconceptualized [Peacocke] |
| 12604 | Any explanation of a concept must involve reference and truth [Peacocke] |
| 4455 | It is always open to a philosopher to claim that some entity or other is unanalysable [Moreland] |
| 18018 | To grasp 'two' and 'green', must you know that two is not green? [Magidor] |
| 18575 | The concepts for a class typically include prototypes, and exemplars, and theories [Machery] |