And, on the other hand, the being of the Antipodes is a necessary interconnected piece in that puzzle of which our astronomical science is the coherent exposition. But if we persisted in our attempt to locate the creature there, we should inevitably bring confusion and contradiction into that sphere of significant being- so far at least as it is manifest to us in our anatomical and physiological knowledge. The horse-man might pass externally as a convenient shape for rapid movement but how about his internal economy, the structure, adjustment and functioning of his inner organs? If he is to be 'actual,' the animal kingdom is his natural home. They collide amongst themselves, or they clash with some of the constitutive elements in that wider sphere of experience, that larger significant whole, in which the Centaur must strive for a place. And in this sense a Centaur is 'inconceivable,' whilst the Antipodes are clearly 'conceivable.' For the elements constitutive of the Centaur refuse to enter into reciprocal adjustment. The elements thus cohering constitute a whole which may be said to control the reciprocal adjustment of its elements, as an end controls its constituent means. A 'significant whole' is such that all its constituent elements reciprocally involve one another, or reciprocally determine one another's being as contributory features in a single concrete meaning. And to be 'conceivable' means to be a 'significant whole,' or a whole possessed of meaning for thought.

To 'conceive' means for us to think out clearly and logically, to hold many elements together in a connection necessitated by their several contents. All this is quite irrelevant, and does not touch our position. Conceivability is the essential nature of truth.' And we may proceed at once to remove a possible misunderstanding of the term 'conceive.' We do not mean by 'conceive' to form a mental picture and we shall not be dismayed when we hear that the Antipodes were once 'inconceivable,' or that a Centaur can be 'conceived.' For it may be difficult-or even, if you like, impossible- to 'image' people walking head downwards and to 'picture' a horse with the head and shoulders of a man may be as easy as you please. It is true because, and in so far as, it can be conceived.

'Anything is true which can be conceived. We may start with the following as a provisional and rough formulation of the coherence-notion.

Logical coherence definition