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Single Idea 19411

[filed under theme 9. Objects / F. Identity among Objects / 7. Indiscernible Objects ]

Full Idea

In nature any straight line you may take is individually different from any other straight line you may find. Accordingly, it cannot come about that two bodies are perfectly equal and alike.

Gist of Idea

In nature there aren't even two identical straight lines, so no two bodies are alike

Source

Gottfried Leibniz (Letters to Burcher De Volder [1706], 1703.06.20)

Book Ref

Leibniz,Gottfried: 'Leibniz Selections', ed/tr. Wiener,Philip P. [Scribners 1951], p.180

A Reaction

Leibniz was very good at persuasive examples! It remains unclear, though, why he takes the Identity of Indiscernibles to be a necessary truth, when he seems to have only observed it from experience. This is counter to his other principles.

The 26 ideas from 'Letters to Burcher De Volder'

13096 The force behind motion is like a soul, with its own laws of continual change [Leibniz]
13177 An entelechy is a law of the series of its event within some entity [Leibniz]
19410 Scientific truths are supported by mutual agreement, as well as agreement with the phenomena [Leibniz]
19409 Soul represents body, but soul remains unchanged, while body continuously changes [Leibniz]
11873 Our notions may be formed from concepts, but concepts are formed from things [Leibniz]
13178 Things in different locations are different because they 'express' those locations [Leibniz]
19411 In nature there aren't even two identical straight lines, so no two bodies are alike [Leibniz]
19412 If two bodies only seem to differ in their position, those different environments will matter [Leibniz]
12747 Monads are not extended, but have a kind of situation in extension [Leibniz]
13179 A complete monad is a substance with primitive active and passive power [Leibniz]
13180 Space is the order of coexisting possibles [Leibniz]
13181 Time is the order of inconsistent possibilities [Leibniz]
13093 The only permanence in things, constituting their substance, is a law of continuity [Leibniz]
19379 The law of the series, which determines future states of a substance, is what individuates it [Leibniz]
13186 Universals are just abstractions by concealing some of the circumstances [Leibniz]
13185 Even if extension is impenetrable, this still offers no explanation for motion and its laws [Leibniz]
13184 The division of nature into matter makes distinct appearances, and that presupposes substances [Leibniz]
13183 Primitive forces are internal strivings of substances, acting according to their internal laws [Leibniz]
12748 Only monads are substances, and bodies are collections of them [Leibniz]
12752 Only unities have any reality [Leibniz]
13182 Changeable accidents are modifications of unchanging essences [Leibniz]
12749 Derivate forces are in phenomena, but primitive forces are in the internal strivings of substances [Leibniz]
13188 The only indications of reality are agreement among phenomena, and their agreement with necessities [Leibniz]
13187 In actual things nothing is indefinite [Leibniz]
12722 Thought terminates in force, rather than extension [Leibniz]
19383 A man's distant wife dying is a real change in him [Leibniz]