Kant’s ideas can be summarized in three major volumes entitled ‘critiques’. They focus on philosophy while applying critical method to philosophical issues. According to Kant, the best and correct method in philosophy involves performing a critique of peoples’ mental faculties rather than speculating on the nature of their world. The method should also involve an investigation of what people believe they know or comprehend coupled with definition of limits of knowledge while determining the mental procedures making sense of the world. Kant referred to the method as the Copernican Revolution in philosophy. Copernicus turned astronomy by arguing that the sun is the center of the solar system. Consequently, Kant turns philosophy by arguing that people can find answers to their philosophical problems by examining their mental faculties. Thus, they should not focus on the metaphysical speculation of the universe. For example, they should acknowledge the revolution affirming that the mind is not a passive receptor as it actively shapes peoples’ perceptions of reality. Kant, however, was quick to note that people do not understand what forms reality. As a result, he developed the philosophy of transcendental idealism to emphasize on the role of mental faculties. He asserted that mental faculties play a vital role of shaping peoples’ experiences to imply a sharp distinction between noumena and phenomena. 
Noumena refer to things-in-themselves or the reality existing independent of peoples’ minds. Conversely, phenomena refer to appearances or the reality established and made sense of in peoples’ minds. Kant asserted that people cannot, with certainty, understand what is out there as their entire knowledge of the external world is filtered through their mental faculties. Thus, people are only capable of understanding the world presented by their minds. Thus, the knowledge of phenomena represents peoples’ entire understanding of the world. As a result, they should accept that they can neither acknowledge nor understand the fundamentals of noumena. Idealism refers to the various strands of philosophy claiming the world is primarily made of mental ideas rather than tangible or physical things. Kant often differs from other idealists as he does not deny that an external reality exists. More so, he does not think that ideas are more fundamental than tangible things. He, however, argues that people can never transcend limitations and contextualization provided by their minds to acknowledge that the only reality they will ever recognize is the phenomena.
Kant also identified the problem of deducing necessary and universal truths from experience Hume. All experience is by its nature contingent and particular. People experience personal sights and sound differently. More so, they cannot experience physical law or causes and effects if they cannot see, hear, or smell the interconnections. Consequently, they cannot infer how some events enable others to occur. Kant questions these concepts in an attempt to determine how synthetic knowledge is possible and utilized in understanding how things are necessary and universal though lacking self-evident and definition. Kant claimed resourceful and inventive solution is based on the assumption that synthetic prior knowledge is possible due to peoples’ mental faculties organizing experiences to suit certain necessary and universal categories and features of their experiences. For example, he asserted that people do not find causation in nature as it is a feature depending on how their minds make sense of reality they perceive causes and effects. Thus, Kant’s category of synthetic a priori is vital in explaining how people gain substantive knowledge about the world.
Ethical theorists are often divided into two. The first category represents ethical theorists considering action as either moral or immoral depending on the motive for which it has been undertaken. Conversely, the second category represents ethical theorists who consider action as either moral or immoral depending on its consequences. Kant is a deontologist rather than a consequentialist with regards to ethics as he considers an action as either immoral or moral depending on its motive. Kant argued that people are subject to moral judgments as they can deliberately provide reasons for their actions. Thus, he believed moral judgment ought to be directed at peoples’ actions. For example, some people can take care to ensure their actions do not lead to negative consequences. The consequences, however, are not subject to peoples’ ways of reasoning. Thus, human beings ought to acknowledge that their actions and reasoning are not fully responsible for the consequences they endorse. They should understand that reasons are only held responsible for endorsing a particular action and the motive behind it should be open to moral judgment.
Ethics of autonomy is a theory applied to differentiate and explain between good and bad. For example, Christians believe a person ought to embrace good ethics as they face the threat of eternal damnation. Conversely, utilitarian’s believe in good rather than bad in pursuit of happiness. Kant, however, asserted that reasoning is the source of morality or good and bad. He claimed that bad actions involve violating maxims laid out by an individual’s reason. It also involves formulating maxims that are not consistent with the universal laws. Thus, Kant argued immorality is an irrational form violating laws of reason hindering people from being moral humans as it comprises their abilities as autonomous beings. For example, he claimed people who behave rationally are autonomous beings in control of their emotions and feelings hence, able to act and support good judgment. In conclusion, Kant’s argument, are developed based on the world history. As a result, they should be applied to settle challenges infringing peoples’ philosophies and social-historical dialectic.
Rohlf, Michael. Immanuel Kant: The Stanford Encyclopedia of Philosophy. Metaphysics Research Lab, Stanford University, 2016.
Michael, Rohlf. Immanuel Kant: The Stanford Encyclopedia of Philosophy. (Stanford University, Metaphysics Research Lab, 2016), 146.
 Michael, Rohlf. Immanuel Kant: The Stanford Encyclopedia of Philosophy. (Stanford University, Metaphysics Research Lab, 2016), 131.
 Michael, Rohlf, 135.
 Michael, Rohlf. Immanuel Kant: The Stanford Encyclopedia of Philosophy. (Stanford University, Metaphysics Research Lab, 2016), 217.
 Michael, Rohlf, 223.
 Michael, Rohlf. Immanuel Kant: The Stanford Encyclopedia of Philosophy. (Stanford University, Metaphysics Research Lab, 2016), 323.