Thomas Henry Huxley 
Method By Which the Causes of the Present and Past Conditions of Organic Nature Are to Be Discovered – the Origination of Living Beings [EPUB ebook] 

pub One.info present you this new edition. In the two preceding lectures I have endeavoured to indicate to you the extent of the subject-matter of the inquiry upon which we are engaged; and now, having thus acquired some conception of the Past and Present phenomena of Organic Nature, I must now turn to that which constitutes the great problem which we have set before ourselves; – I mean, the question of what knowledge we have of the causes of these phenomena of organic nature, and how such knowledge is obtainable.