The following letters from Marlborough Place show him at work upon the book:—­]

March 31, 1878.

My dear Morley,

I like the notion of undertaking your Hume book, and I don’t see why I should not get it done this autumn.  But you must not consider me pledged on that point, as I cannot quite command my time.

Tulloch sent me his book on Pascal.  It was interesting as everything about Pascal must be, but Tulloch is not a model of style.

I have looked into Bruton’s book, but I shall now get it and study it.  Hume’s correspondence with Rousseau seems to me typical of the man’s sweet, easy-going nature.  Do you mean to have a portrait of each of your men?  I think it is a great comfort in a biography to get a notion of the subject in the flesh.

I have rather made it a rule not to part with my property in my books—­but I daresay that can be arranged with Macmillan.  Anyhow I shall be content to abide by the general arrangement if you have made one.

We have had a bad evening.  Clifford has been here, and he is extremely ill—­in fact I fear the worst for him. [See below.]

It is a thousand pities, for he has a fine nature all round, and time would have ripened him into something very considerable.  We are all very fond of him.

Ever yours very faithfully,

T.H.  Huxley.

July 6, 1878.

My dear Morley,

Very many thanks for Diderot.  I have made a plunge into the first volume and found it very interesting.  I wish you had put a portrait of him as a frontispiece.  I have seen one—­a wonderful face, something like Goethe’s.

I am picking at Hume at odd times.  It seems to me that I had better make an analysis and criticism of the “Inquiry,” the backbone of the essay—­as it touches all the problems which interest us most just now.  I have already sketched out a chapter on Miracles, which will, I hope, be very edifying in consequence of its entire agreement with the orthodox arguments against Hume’s a priori reasonings against miracles.

Hume wasn’t half a sceptic after all.  And so long as he got deep enough to worry Orthodoxy, he did not care to go to the bottom of things.

He failed to see the importance of suggestions already made both by Locke and Berkeley.

Ever yours very faithfully,

T.H.  Huxley.

September 30, 1878.

My dear Morley,

Praise me!  I have been hard at work at Hume at Penmaenmawr, and I have got the hard part of the business—­the account of his philosophy—­blocked out in the bodily shape of about 180 pages foolscap manuscript.

But I find the job as tough as it is interesting.  Hume’s diamonds, before the public can see them properly, want a proper setting in a methodical and consistent shape—­and that implies writing a small psychological treatise of one’s own, and then cutting it down into as unobtrusive a form as possible.