Philosophy of nature, known in Latin as philosophia naturalis, was the precursor of what is now called natural science, especially physics. For example, Isaacus Newtonus (http://la.wikipedia.org/wiki/Newtonus)'s treatise Principia Mathematica Philosophiae Naturalis which founded modern physics (modern compared to ancient physics, that is), means Mathematical Principles of the Philosophy of Nature.
Philosophy of nature includes physics (see Archimedes of Syracuse, Heron of Alexandria) biology, which was founded by Aristotle, "the father of biology", and astronomy (see Eudoxus of Cnidus, astronomer).
Philosophy of nature became science (scientia in Latin, which means "knowledge") when inductive methods of knowledge acquisition, known as the scientific method became emphasized over pure deduction.
The ancient emphasis on deduction has its representative in Aristotle's Organum, and the new emphasis on induction and research has its representative in Francis Bacon's treatise Novum Organum.
Philosophy of nature also can include: geology, gemmology, chemistry, paleontology. Philosophy of nature does not include: psychology, sociology, ethics, esthetics, politics, theology, philosophy of mind, philosophia perennis, history, axiology, rhetoric, oratory, consciousness, anthropology.
In René Descartes' metaphysical system of dualism, there are two kinds of substance: matter and mind. According to this system, everything which is "matter" is deterministic and natural -- and so belongs to philosophia naturalis -- and everything which is "mind" is volitional and non-natural, and falls outside the domain of philosophy of nature.
- Past Exhibit in Philosophical Hall (http://www.amphilsoc.org/exhibitions/philhall.htm) by APS.