The discipline of philosophy looks at the meaning of life, considering topics and questions surrounding human existence and experience, society, knowledge, and the universe. There are many branches of philosophy, the main ones being logic, or the structure of argument and rational thought; metaphysics, the study of all that exists; epistemology, which studies knowledge; and axiology, which includes the study of ethics and aesthetics.
New findings in psychology and neuroscience are pushing philosophers to rethink such big questions as the relationship between mind and body, the meaning of free will, just exactly what faith is, the nature of consciousness, and what constitutes happiness. There's some evidence that issues such as free will itself reflect temperament and personality. There's even more evidence that we are terrible at predicting what will make us happy, which is why we have such a hard time finding durable happiness.