"basic limiting principles" in at least five ways: Backward causation (i.e., the future affecting the past) is rejected by many philosophers, but would be shown to occur if, for example, people could predict the future. One common argument against dualism (i.e., the belief that, while bodies are physical entities, minds are a different, non-physical sort of entity) is that physical and non-physical things cannot interact. However, this would be shown to be possible if people can move physical objects by thought (telekinesis). Similarly, philosophers tend to be skeptical about claims that non-physical 'stuff' could interact with anything. This would also be challenged if minds are shown to be able to communicate with each other, as would be the case if mind-reading is possible. Philosophers generally accept that we can only learn about the world through reason and perception. This belief would be challenged if people were able to psychically perceive events in other places. Physicalist philosophers believe that there cannot be persons without bodies. If ghosts were shown to exist, this view would be challenged. Free will In his essay "Determinism, Indeterminism, and Libertarianism", Broad argued for non-occurrent causation as "literally determined by the agent or self." The agent could be considered as a substance or continuant, and not by a total cause which contains as factors events in and dispositions of the agent. Thus, our efforts would be completely determined, but their causes would not be prior events. New series of events would then originate, which he called "continuants", which are essentially causa sui. Peter van Inwagen says that Broad formulated an excellent version of what van Inwagen has called the "Consequence Argument" in defence of incompatibilism. Works 1914. Perception, physics and reality. An Enquiry into the Information that Physical Science can Supply about the Real. London: Cambridge University Press. . 1923. Scientific thought. New York: Harcourt, Brace and Co. (). 1925. The Mind and Its Place in Nature. London: Kegan. 1926. The Philosophy of Francis Bacon. Cambridge: Cambridge University Press. 1930. Five types of ethical theory. New York: Harcourt, Brace and Co. 1931. War Thoughts in Peace Time. London: Humphrey Milford. 1933. Examination of McTaggart's philosophy. Vol. 1. Cambridge University Press. 1934. Determinism, interdeterminism and libertarianism. Cambridge: Cambridge University Press. 1938. Examination of McTaggart's philosophy. Vol. 2. Cambridge University Press. 1952/2000. Ethics and the History of Philosophy. Routledge. . 1953/2000. Religion, Philosophy and Psychic Research. Routledge. . 1955.