“Great powers have never been exerted independent of strong feelings. The rapid arrangements of ideas, from their various analogies to the equally rapid comparisons of these analogies, with facts uniformly occurring during the progress of discovery, have existed only in those minds where the agency of strong and various motives is perceived--of motives modifying each other, mingling with each other, and producing that fever of emotion, which is the joy of existence and the consciousness of life.” The following extracts relate to science and philosophy:-- “Philosophy is simple and intelligible. We owe confused systems to men of vague and obscure ideas.” “We ought to reason from effects alone. False philosophy has uniformly depended upon making use of words which signify no definite ideas.” “Experimental science hardly ever affords us more than approximations to truth; and whenever many agents are concerned we are in great danger of being mistaken.” “Scepticism in regard to theory is what we ought most rigorously to adhere to.” “The feeling generally connected with new facts enables us to reason more rapidly upon them, and is peculiarly active in calling up analogies.” “Probabilities are the most we can hope for in our generalisation, and whenever we can trace the connection of a series of facts, without being obliged to imagine certain relations, we may esteem ourselves fortunate in our approximations.” “One use of physical science is, that it gives definite ideas.” To the same period belongs the sketch or plan of a poem, in blank verse, in six books, on the deliverance of the Israelites from Egypt, which either Southey or Coleridge had proposed to him as a joint-work, fragments of which are to be found amongst the note-books. Towards the end of 1800 Davy’s visions of future greatness began to take more definite shape. This is hinted at in the letter from Coleridge of October 9th, 1800, already given, and also in one to his mother, dated September 27th, 1800, in which he says, “My future prospects are of a very brilliant nature, and they have become more brilliant since I last wrote to you; but wherever there is uncertainty I shall refrain from anticipating.” In a few months the uncertainty was practically at an end. He had been drawn into the great vortex called London, “full,” as he says in a letter to Hope, “of the expectation of scientific discovery from the action of mind upon mind in this great hot-bed, of human power.” He thus informs his mother:-- “_31st January, 1801._