Critical thinking is a rich, dynamic, complex concept that entails bringing the most appropriate and highest standards for thought to bear upon the intrinsic (and frequently flawed) reasoning that occurs in the human mind, in order to reason at the highest levels. Critical thinking, in its explicit form, requires disciplining one’s own thinking, as well as understanding and evaluating others’ thinking, by focusing deliberately on the components present in all human reasoning. It requires developing executive-level functioning, in which the mind examines and re-examines its own thought by reasoning about its thinking to improve its reasoning. An early 1980s quote, often repeated by Richard Paul, that captures this point in a catchy phrase is: ‘thinking about your thinking while you’re thinking to improve your thinking’. This entails identifying and examining any errors or problems in the components, or elements, of reasoning, and correcting flaws by employing criteria appropriate in a given context. This systematic process, daily and routinely applied, should increasingly improve one’s reasoning abilities over time. This in turn should lead to progressively more insightful levels of self-awareness on the part of the reasoner and, were it to be taken seriously on a broad scale, on the species itself.

Critical thinking should lead to a world in which the majority of people, through their thinking, are able to make meaningful contributions and find contentment, despite the many complexities we face. Critical thinking arises from the need to intervene in the mistaken, irrational, and self-deceptive reasoning pervasive in human societies, which requires cultivating traits of mind, as well as skills and abilities.

Critical thinking entails getting underneath and examining social norms, conventions, and taboos to determine the extent to which they are logical and reasonable. It might be noted that not every critical thinking theoretician accepts or advances the importance of ethical reasoning in critical thinking. Yet critical thinking as a serious field of study would guide reasoners to embrace and develop within themselves intellectual as well as ethical virtues that gradually improve and enhance their character as fair-minded persons; this follows from the ethical obligations all people face in living a human life.

Critical thought differs in logic from any other field in that it attempts to understand thought itself – what thought entails, and where it goes wrong; it attempts this, in part, by uncovering, examining, and appreciating the many ways in which skilled, committed, passionate human thought leads to a more reasonable world, as well as the many ways in which confusions, delusions, and deceptions in human thought lead to a less reasonable world. In its highest manifestations, critical thinking searches for understandings and practices that advance life on the planet. In short, critical thinking is separate from, but necessary to, every subject, discipline, profession, or arena of human life that entails reasoning; this includes virtually every domain of life, to some degree, since reasoning is naturally occurring in the mind.

Critical thinking searches for patterns of intrinsic neurotic and pathological reasoning that impede our capacities for criticality, logical thought, and reasonability. Critical thinking seeks to understand human reasoning as a system of ideas intimately connected with other fundamental functions of the human mind, namely emotions and desires (the affective dimension). Because thinking coexists in relationship with feelings and the human will, critical thinking theoreticians attempt to understand the concomitant relationships among thinking, emotions, and desires, and to uncover the conceptual tools most useful in improving not only cognition, or thinking, but also emotions and desires. Critical thinking is meant to be pre-eminently practical; it seeks to establish and develop universal concepts and principles about human thought essential to advanced reasoning in any field of study. By improving reasoning, these universal principles are essential as well to improving human life.

In sum, guiding conceptual principles for human reasoning, and hence human life, are explored, established, and cultivated through the field of critical thinking studies.

Critical thinking advances freedom of thought, which presupposes freedom of speech. This follows precisely because freedom of speech is required if humans are to openly and unreservedly explore thought without fear of reprisal or punishment, and if they are to best explore the many various and frequently complex implications of thought. Critical thinking helps explore all domains important to living a fulfilling life, including the psychological, social, economic, ecological, zoological, historical, scientific, literary, sexual, artistic, civic, and political. And critical thinking is essential to the cultivation of the educated mind (see Education).

Historically, a number of important theoreticians have contributed to a shared conception of critical thinking. These include theoreticians reaching back in time before the use of the term critical thinking, as well as those theoreticians who began articulating an explicit concept of critical thinking in the 1970s and 80s. For instance, some of the roots of contemporary critical thinking began in the early part of the twentieth century, from fields such as logical positivism, analytic philosophy, and semantics. Many of the latter theoreticians came from philosophy departments, primarily those interested in formal logic, informal logic, and argumentation. Beginning in the 1970s and moving through the 1980s and 90s, various fields of study began to contextualise and develop aspects of critical thinking at differing levels of quality.

The most comprehensive and integrated approach to critical thinking was developed by Richard Paul (1937–2015) and continues with the writings and teaching of scholars working in the Paulian tradition. Paul’s approach is distinguished from other critical thinking theories chiefly because it offers the most comprehensive, integrated approach to critical thinking, is it essential to reasoning through the questions and problems in academic and professional disciplines, and is based in ordinary languages. Paul argues for living the examined life, in connection with the thinking of Socrates. Paul’s framework establishes first principles in critical thinking that may be derived from the theory he constructed, distilled, and developed. Notably, Paul emphasises ethical reasoning as essential to critical reasoning, the importance of deliberate self-cultivation in advancing one’s own intellectual character, and the universals in reasoning applicable across all domains of thought, subjects, and disciplines.