The Second Wave of Critical Thinking

A balanced approach to a misunderstood concept.

Posted May 26, 2020

The concept of critical thinking is clearly important. There is widespread acceptance that we would do better if there was more critical thinking. Society would benefit. Students would do better in schools. People would be more successful in their personal and professional lives.

We generally view critical thinking as making judgments based on the systematic analysis of evidence of some problem or topic, rather than relying on impulses, opinions, and emotions. That’s the standard approach, which is the first wave of conceptualizing critical thinking.

While the concept of critical thinking can be traced back to Socrates and the Socratic dialogue, interest in training critical thinking skills in the United States rapidly grew after the 1983 publication of A Nation at Risk, which described declines in national academic performance and SAT scores. 

However, there is a second wave which is a more recent development. The second wave refers to thinking clearly about what is going on around us, and not uncritically accepting what people tell us is happening. It's about thinking for ourselves, asking ourselves, "is this explanation plausible?"

In his 1994 book Re-Thinking Reason, Kerry Walters explained how the first wave concentrated on logical reasoning and the “calculus of justification.” The second wave appreciated the importance of imagination, creativity, intuition, and insight. 

The first wave is about how we think. The second wave is about what we can discover.

Both waves have value. By disentangling them, perhaps we can find better ways to improve critical thinking and reach a more balanced view of it.

The First Wave of Critical Thinking 

The first wave is about trying to reduce errors and illogical reasoning. Critical thinking should be thorough and systematic, rigorous, consistent, logical, and it should rely on reliable evidence. In the System 1/System 2 formulation of cognition, the first wave aligns with System 2.

The first wave has received most of the attention thus far when it comes to critical thinking. I have reviewed some of this literature (Klein, 2011) to capture the kinds of guidance being offered: If we want to strengthen the first wave of critical thinking, we are advised to check our assumptions and to identify the areas of uncertainty that might cloud our judgments. We should worry about inconsistencies and should review our arguments and beliefs and assumptions to try to maintain internal consistency because otherwise we can fool ourselves and draw invalid conclusions.

All of these suggestions are undoubtedly familiar to readers. The Wikipedia entry on critical thinking offers a comprehensive summary of the different aspects of the first wave.

In my 2011 article, I also discussed the dangers of over-emphasizing the processes described by the first wave. Most organizations concentrate on the first wave because it is easier to catch errors than to notice when insights got missed. However, we need to be careful not to put so many restrictions on reasoning and inferences that we inhibit creativity. 

For example, if we are encouraged to consider all relevant hypotheses, the flood of possibilities may make it harder to judge what is going on. If we spend our time tracking assumptions and uncertainties, checking the pedigree of sources, and checking for logical inconsistencies, we may not have the remaining bandwidth to gain insights. If we require people to justify their conclusions, they will likely attend to cues that they can verbalize and ignore the tacit knowledge that is the core of expertise. And following the requirement for checking assumptions, maintaining internal consistency, and so forth may encourage a passive mindset of trying not to make mistakes rather than an active mindset of trying to make discoveries.

The Second Wave of Critical Thinking

The second wave encourages us to use our own judgment about what’s happening in situations and what should be happening. Instead of blindly accepting the interpretations of others and passively following orders, we can do more to actively make sense of events.

We can be alert to weak signals that others aren’t noticing. We can become curious about coincidences and possible connections. We can be sensitive to events that were supposed to happen but didn’t. We can be more mindful. Curiosity appears to be a common denominator for all of these aspects of the second wave of critical thinking.

One aspect of critical thinking is a shift in mindset, from a procedural mindset to an investigative mindset. The procedural mindset is that all we need to do is to follow the procedures. Certainly, in most jobs, we need to learn the procedures. But sometimes the rules and procedures don’t apply or would lead to poor outcomes. Procedures are necessary, but they aren’t sufficient. We need to learn the procedures but shouldn’t get trapped by them. We also need to look around.

This mindset shift, from procedural to investigative, has come up in many different professional settings that I study, such as Child Protective Services. Caseworkers are responsible for keeping children safe after an incident or a report that suggests possible harm. Caseworkers are given training and even checklists for how to conduct site visits and interviews.

But that’s not enough. You can’t have checklists for what might be dangerous for a specific family in a specific home or living arrangement. A good caseworker needs to go beyond the procedures to imagine what might go wrong, what kinds of risks might emerge.

Here we are in the realm of detecting problems — anticipating dangers. There are no procedures for identifying danger. A caseworker who is a first-wave critical thinker might think his/her job was done after completing all the steps of the checklist and might miss trouble spots not covered in the checklist. When senior administrators in Child Protective Services complain that young caseworkers aren’t showing enough critical thinking, they refer to the second wave and being alert to the hazards in a specific home for a specific family.

The second wave of critical thinking also encourages us to question the goals we have been given. It is so easy to mindlessly pursue the official goals and objectives — the ones issued by our organization or by our boss. However, in complex and changing situations, these goals may be overtaken by events. Or we may be up against wicked problems with no definitive goals and we’ll need to revise the goals as we proceed. I have referred to this process as Management by Discovery: the need to adapt and improvise, not simply the tactics for achieving the goals, but to rethink the goals themselves. 


My purpose in writing this essay was to offer a broader perspective of critical thinking, encompassing both the first and the second waves. The first wave has initiated many thoughtful and useful ideas and programs (e.g., Halpern, 2007). 

The second wave is an important balance to the first. It develops programs and methods to prepare decision-makers to independently assess what is happening and what goals they should be pursuing. Hopefully, the future will see additional progress in strengthening both aspects, the first and second waves of critical thinking.


Halpern, D.F. (2007). The nature and nurture of critical thinking. In R.J. Sternberg, H.L. Roediger III, & D.F. Halpern (Eds.). Critical thinking in psychology. New York, N.Y.: Cambridge University Press.

Klein, G. (2011). Critical thoughts about critical thinking. Theoretical Issues in Ergonomics Science, 12 (3), 210-224.

National Assessment of Education Progress. (1983). A nation at risk. Washington, DC: U.S. Government Printing Office.

Walters, K. (1994). Re-Thinking Reason: New perspectives in critical thinking. SUNY Press.