‘Critical thinking’ is a descriptive phrase used widely both within Singapore and, increasingly, in discussions of education throughout the world. Many educators at the tertiary level would feel that helping students to develop and strengthen the capacity to think critically is an important objective of their pedagogy, and yet would differ about the precise characterization of what they try to inculcate. Most would agree, however, that critical thinking attempts to prevent the unquestioning adoption of ideas without careful consideration. They would also agree that its goal is critical evaluation, paying attention to both the positive and the negative aspects of what is being evaluated.

To clarify the concept of critical thinking further, it might be useful to consider examples of activities that crucially call for the exercise of critical thinking:

• A reviewer critically evaluating a research article submitted to a journal, to make a recommendation on its publication.
  
• A mathematician checking the validity of a proposed proof for a theorem.
  
• A law professor critically evaluating the moral codes, political ideologies and group interests underlying the laws of a country.
  
• A Department committee evaluating the quality of the teaching, research, and service of a faculty member to make a recommendation on promotion and tenure.
  
• A museum curator evaluating the quality of a painting.
  
• The members of a jury scrutinizing the evidence and argumentation presented by the lawyers to arrive at a verdict on the guilt of the accused.
  
• The members of a cabinet debating the desirability of a proposed policy.
  
• The director of a corporation considering an application for funding a research project.
  
• a social activist judging how to make a strategic intervention that will benefit society.
  
• a person attempting to understand how he or she is privileged or disadvantaged by social institutions.
  
• an individual attempting to see the world in which she or he lives through the eyes of others with radically different epistemological assumptions.
  
• A farmer making an informed decision on the use of genetically modified seeds.
  
• A reader evaluating the credibility of a newspaper report.
  
• A citizen making a decision on who to vote for.

As can be seen from such examples, critical thinking refers to a collection of overlapping mental activities of intuiting, clarifying, reflecting, connecting, inferring, judging, and so on. It brings these activities together to evaluate the credibility, quality, impact, significance, usefulness or desirability of an entity on the basis of an implicit or explicit value system and a set of criteria of evaluation. The entity being evaluated can be a knowledge claim, a research article, a work of art, a funding proposal, a social practice, an institution, a person, and so on, with the factors relevant for the evaluation varying accordingly.

Needless to say, there is considerable overlap between the thinking processes involved in creating something and evaluating something. In the context of academic inquiry, for instance, both the writer of a scientific article and its reviewer need to pay attention to matters of methodology, reasoning, and competing alternatives, drawing upon both creative and critical faculties. It is nevertheless useful to make a distinction between the two modes of thinking in terms of the shifts of emphasis stemming from their respective functions: the creator of research finds worthwhile problems or questions and proposes solutions or answers, the critic evaluates the answers.

What are the kinds of critical thinking abilities that are valuable for educated individuals? As a first approximation, one may identify the following broad categories, no doubt with considerable overlap:

• Discipline specific critical thinking, as manifested in the ability to evaluate the credibility (and significance) of the research findings/claims of research articles/papers and books in the area of one’s specialization (e.g., a biology major critically evaluating a biology paper in Nature; a cultural studies major critically evaluating Thomas Kuhn’s contribution to our understanding of the evolution of knowledge.) Depending upon the area of academic inquiry, this may subsume thinking critically about research claims, frameworks, ideas, social and institutional practices, value systems, implicit assumptions and ideologies, and so on.

• General purpose critical thinking, which involves four related domains, namely:

  1. The academic domain: the ability to evaluate the credibility and significance of the claims in articles and books written for educated lay readers (e.g., a history major critically evaluating an article in Economist or New Scientist).

  2. The professional domain: the ability to evaluate options in one’s professional life (e.g., the director of a company evaluating the proposal for a company policy).

  3. The public domain: the ability to evaluate ideas and policies, formulate informed opinions and participate in public matters as responsible citizens (e.g., an engineer thinking through the system of capital punishment).

  4. The private domain: the ability to evaluate options in one’s private life (e.g., a patient making an informed decision on whether to undergo surgery.)

An articulation of the value system and criteria that underlie the different types of critical thinking, the kinds of mental activities they draw upon, and the kinds of grounds they are based on, can inform pedagogical choices and practices, and result in useful ideas for

• the design of new undergraduate modules on discipline specific and/or general purpose critical thinking, and
  
• the incorporation of critical thinking into existing content modules and research methodology modules.

Drafted by K P Mohanan () and revised on the basis of detailed input from Helmer Aslaksen, Wang Chien Ming, John Richardson, Philip Holden, Sunita Abraham, and Tara Mohanan. Likely to be revised further on the basis of further input from others.