These three essays by an eminent philosopher and scientist were written originally for The Monist andappeared in that magazine between 1901 and 1903. They explore the nature, origin, and development of our concepts of space from the points of view of the senses, history, and physics. Most books on the foundations of geometry emphasize only a single perspective - that of logic, epistemology, psychology, history, or the formal technology of the science. These authoritative essays examine the subject from every direction, and with distinctness and precision. Entitled
On Physiological, as Distinguished from Geometrical, Space,

On the Psychology and Natural Development of Geometry,
and
Space and Geometry from the Point of View of Physical Inquiry,
their accessible form makes them suitable for both undergraduate students and other readers.