The mind-body problem and the problem of other minds, two of the fundamental problems in the philosophy of mind, are implicitly debatable issues in modern legal systems. Folk psychology, different views on the term "free will" and neurophysiological studies which are all closely related to these philosophical issues provide a basis for interpreting criminal law in modern legal systems. The aim of this essay is to analyze the approaches to the philosophical questions mentioned and the effects of these approaches on criminal law. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get the original essay Dualism and monism are two inverse approaches to the mind-body problem that study how the mind and body interact with each other. The question is whether the mind is the same thing as the brain which is part of the body or whether it is a separate and different entity from the brain. Dualism holds that mind and body are two distinct essences, the first is non-physical and the second is physical, and conscious intelligence is formed of non-physical essence. Additionally, in Cartesian dualism, the mind is seen as an entity entirely independent of the world that people can perceive with their senses. On the other hand, monism attempts to explain the mind-body problem with a single essence. It holds that mind and body are identical and not separate substances. In reductive materialism, considered a form of monism, mental states are considered physical states of the brain and derive from activities within the central nervous system. Besides the mind-body problem, the problem of other minds is trying to find an explanation for the problem. the question of how the mental states of others are perceived. In Cartesian dualism, mental states as non-physical states separate from the body are personal experiences and can be experienced distinctly from one body to another. Mental states are therefore states unobservable for an observer who does not experience them personally. Thus, philosophical behaviorism, in reaction against dualism, considers the Cartesian vision of the mind as a “ghost in the machine”. Philosophical behaviorism holds that non-physical mental states do not exist beyond the physical state, the brain, and that any mental state can be perceived by interpreting observable behaviors or circumstances. Behaviors are reflections of mental states in the physical world. Common sense folk psychology is a theory that draws on the behaviorism approach to address the problem of other minds. The theory attempts to explain and predict the mental states behind the behaviors of others. Folk psychology involves several predictions based on people's past mental behavioral experiences and represents causality between mental process and behaviors. According to David Lewis, common-sense folk psychology involves claims about mental states that almost everyone agrees with and takes to be self-evident. Criminal law benefits from folk psychology to determine the internal states of a crime in addition to the physical states, “actus raus”. The beliefs, desires or motivations in the inner states of people who undertake an action play a crucial role in the criminalization of that action. As mentioned, crimes have both mental and physical elements and intentionality is one of the important criteria in the prediction processmental states. Common sense folk psychology allows people to decide whether an action is brought intentionally, for a specific purpose or not in modern legal systems. However, are there cases where people bring an action with an intention that is not their own intention or will? Here another philosophical question is revealed which also finds its place in criminal law; problem of free will and determinism. Free will, as a definition, is controlling and determining the actions of people based on their desires, intentions, and goals.Free will is the power to freely use the mind and the power to decision-making and application of living beings, without any coercion or external necessity; action is the ability to initiate action. Free will is therefore a prerequisite for morality, personal choices and responsibility. Cartesian dualism is an argument in favor of free will in the sense of freedom of mind. Supporting this mind is a separate entity from the body and the conscious activities that take place in the mind provide a basis for free will. Conscious activities are not manipulated by bodily or environmental factors because they are independent of them. On the other hand, determinism as a theory suggests that events that occur in the environment are determined by various scientific and physical laws and that these specified events must be accomplished. . According to determinism, everything is determined and cannot be modified. The universe is therefore independent of the will of the observer. Determinism is thus opposed to free will. It asserts that the decisions, thoughts, actions, and moral preferences that people make in daily life and consider unique to themselves are determined and subject to strict rules. People make their decisions not consciously but based on mechanical, economic, social, historical, experimental, psychological, sociological, moral and legal determinism. Free will only develops within a causal chain in which there is no human influence. Free will is therefore an illusion. In this context, the concepts of "caste", "conscience" and "will" have had great importance and have given rise to numerous controversies in the evolution of criminal law. In modern legal systems, the notions of responsibility, crime and punishment cannot be evoked without free will. Therefore, free will must be assumed to establish a criminal legal system. For a person to be punished, it is not enough to observe an act contrary to the law. At the same time, it is necessary to find out whether there is a “caste” or a “will” in the commission of the act. The term "guilty mind" is used to mean that an unintentional act, although contrary to the law, will not constitute a criminal offense. In this way, determinism alone cannot find its place in the modern legal system due to the necessity of free will. Accordingly, it can be said that incompatibilism, supported mainly by libertarians, does not constitute an overall thesis for criminal law as well. Libertarianism suggests that free will is real and certainly incompatible with determinism; determinism must therefore be false. However, criminal law uses deterministic elements in some cases, such as those that include "self-defense" or "incitement", and it accepts the existence of free will. Concordantly, both determinism and indeterminism are antagonistic as situations contrary to human reality. It is therefore obvious that the compatibilist thesis which establishes a link between free will and.