shows very well his own
interest and that of his generation in physical science of all kinds.
There were eight treatises on Aristotle's physics and on the underlying
principles of natural philosophy and of energy and of movement; four
treatises concerning the heavens and the earth, one on physical
geography which also contains, according to Pagel, numerous suggestions
on ethnography and physiology. There are two treatises on generation and
corruption, six books on meteors, five books on minerals, three books on
the soul, two books on the intellect, a treatise on nutritives, and then
a treatise on the senses and another on the memory and on the
imagination. All the phases of the biological sciences were especially
favorite subjects of his study. There is a treatise on the motion of
animals, a treatise in six books on vegetables and plants, a treatise on
breathing things, a treatise on sleep and waking, a treatise on youth
and old age, and a treatise on life and death. His treatise on minerals
contains, according to Pagel, a description of ninety-five different
kinds of precious stones. Albert's volumes on plants were reproduced
with Meyer, the German botanist, as editor (Berlin, 1867). All of
Albert's books are available in modern editions.

Pagel says of Albertus that

His profound scholarship, his boundless industry, the almost
incontrollable impulse of his mind after universality of
knowledge, the many-sidedness of his literary productivity,
and finally the almost universal recognition which he received
from his contemporaries and succeeding generations, stamp him
as one of the most imposing characters and one of the most
wonderful phenomena of the Middle Ages.

In another passage Pagel has said:

While Albert was a Churchman and an ardent devotee of
Aristotle, in matters of natural phenomena he was relatively
unprejudiced and presented an open mind. He thought that he
must follow Hippocrates and Galen, rather than Aristotle and
Augustine, in medicine and in the natural sciences. We must
concede it a special subject of praise for Albert that he
distinguished very strictly between natural and supernatural
phenomena. The former he considered as entirely the object of
the investigation of nature. The latter he handed over to the
realm of metaphysics.

Roger Bacon is, however, the one of these three great teachers who
shows us how