Condensed matter physics

Whilst Copernicus has persuaded us to believe, contrary to all the senses, that the earth does not stand fast Boscovich has taught us to abjure the belief in the last thing that stood fast of the earth—the belief in "substance," in "matter," in the earth-residuum, and particle-atom: it is the greatest triumph over the senses that has hitherto been gained on earth. One must, however, go still further, and also declare war... against the "atomistic requirements" which still lead a dangerous after-life in places where no one suspects them, like the more celebrated "metaphysical requirements": one must also above all give the finishing stroke to that other and more portentous atomism which Christianity has taught best and longest, the soul-atomism. Let it be pemitted to designate by this expression the belief which regards the soul as something indestructible, eternal, indivisible, as a monad, as an atomon : this belief ought to be expelled from science!

My opinion concerning God differs widely from that which is ordinarily defended by modern Christians. For I hold that God is of all things the cause immanent, as the phrase is, not transient. I say that all things are in God and move in God, thus agreeing with Paul, and, perhaps, with all the ancient philosophers, though the phraseology may be different ; I will even venture to affirm that I agree with all the ancient Hebrews, in so far as one may judge from their traditions, though these are in many ways corrupted. The supposition of some, that I endeavour to prove in the Tractatus Theologico-Politicus the unity of God and Nature (meaning by the latter a certain mass or corporeal matter), is wholly erroneous.

The supreme task of the physicist is the discovery of the most general elementary laws from which the world-picture can be deduced logically. But there is no logical way to the discovery of these elemental laws. There is only the way of intuition, which is helped by a feeling for the order lying behind the appearance, and this Einfühlung [literally, empathy or 'feeling one's way in'] is developed by experience.