Benjamin Collins Brodie to Faraday   14 January 1859

14 Saville Row W | January 14, 1859.

My Dear Sir

Pray do not think that in what I said last night¹ I alluded in any way to the observations made in a lecture of yours formerly on the force of gravity ²; which indeed were not at the time at all present to my mind, & which, if my recollection be accurate, were based on an entirely different view of the subject.

All that I intended to say was that in physics not less than in metaphysics, there are boundaries beyond which, not only from the want of opportunities of experience, but also from the want of adequate powers of comprehension, the Human Intellect can not penetrate; & that we must be content to accept certain facts as well established, of which we can offer no explanation by referring them to any more general principle. For example: that there are good grounds for believing that there is something pervading the universe corresponding to Newtons notion of an Ether, I do not doubt; but if we venture further than this, & attribute the mutual attraction of masses of matter to the operation of such an ether, we do but substitute one simple fact for another simple fact, & endeavour to explain one thing by another thing which is equally inexplicable.

I dare say that you have forgotten, but I have not forgotten a conversation which I had with you long ago, in which I believe that you expressed yourself as agreeing with me in the opinion that of the ultimate structure of material bodies we neither know, nor can have any actual knowledge, & that neither the ordinary hypothesis of solid impenetrable molecules, nor Boscovich’s³ hypothesis of mathematical points, which are centres of attraction & repulsion, is anything more than a contrivance for bringing these things down to the level of all limited comprehension⁴.

I owe you some apologies for occupying so much of your time, & I can only make up for it by asking you not to think it necessary to take the trouble of writing an answer to what I have written.

Yours most truly | B.C. Brodie

M. Faraday Esqr.