In trying to find answers to these questions, lots of other problems arise, many of them fascinating in their own right. Anyone who has ever asked questions like these has already started to do philosophy. Philosophy is one of the world's oldest subjects of study. In ancient Greece, philosophers pursued many questions which would nowadays be regarded as scientific as well as philosophical ones. During the sixteenth century, physics became a separate subject, and in the nineteenth century psychology gradually developed a separate identity.
New subjects continue to emerge from work in philosophy.
These include areas like cognitive science where philosophers, psychologists and computer scientists work with other experts to try to unravel the nature of intelligent systems and to understand consciousness, thinking, speech and reason. Philosophy cannot be learnt by rote or from a text book. Studying it in depth develops reasoning powers by requiring focus on some of the most difficult, abstract and persistently worrying questions that have always engaged reflective people. Philosophical studies leave a deep mark on the mind, and provide intellectual virtues in demand beyond the university. Employers are becoming increasingly aware of the value of the imagination and rigour which philosophy students need to acquire.