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difference in method indicating the great importance of modern 
advance in this particular direction. 
Thus it was that the language of “ scientific 33 opinion at 
the time referred to was moulded in accordance with the 
prevailing tendency of thought of the period, that tendency 
includiug within it the two very powerful elements of credulity 
and superstition. How far the same principle applies at the 
present day, we shall see as we proceed with this paper. 
Here, however, I would beg to interpolate an explanatory 
remark. It is, that in the observations about to follow, I 
purposely omit the names of living men whose views I quote, 
my sole object being to deal with opinions, not with men as 
individuals. In the references given in foot-notes, however, 
means are afforded for tracing the various authors quoted. 
With certain of the views to be noticed I find myself in 
accord; with others, however, I have the misfortune to be 
absolutely at variance ; therefore it is that in this address I am 
especially desirous to avoid every appearance of personality. 
4. But Theophrastus Bombastus von Hohenheim had not in 
reality altogether evolved from his inner consciousness, even 
by the aid of the ghosts of Galen and Avicenna, the theories 
which, coming from a man of his high intellectual and moral 
standing, as already shown, attained the great popularity 
accorded to them by the learned of that time. His theories 
were in fact a reproduction, but with a modification, of others 
not less than nineteen hundred years old, even at the date when 
he appropriated or imitated them. Their originals, in several 
respects at least, are to be found in the philosophy of Demo- 
critus, regarding whom and which a few remarks are here 
deemed a prop os. His birth is variously assigned to b.c. 494 
and 460; he died b.c. 361. According to his doctrine, all that 
exists is vacuum and atoms. The atoms are the ultimate 
material of all things, including spirit. They are uncaused, 
and have existed from eternity. They are invisible, but 
extended, heavy, and impenetrable. They vary in shape. 
They are in motion, and this motion is eternal. There 
is an innate necessity by which similar atoms come to- 
gether. Soul and fire are of one nature ; the atoms of which 
they consist are small, smooth, and round. It is by inhaling 
and exhaling such atoms that life is maintained. It follows 
that the soul perishes with, and in the same sense as, the body. 
There is, in fact, no distinction made between the principle 
of life and the higher mental faculties. He considered that 
sensation is our only source or faculty of knowledge ; he 
admits no mental faculty apart from sensation. Tradition 
attributes to him such sayings as : “ There is nothing true ; 
