Theory and Practice

Recently I have been following a series of discussions on Facebook on the relative merits of compressed air foam (CAF) versus water as an extinguishing agent. Some of my colleagues profess that CAF is superior in all respects and in all applications for extinguishment by cooling. Others point to the limited ability to cool hot gases when dealing with a shielded compartment fire as a major problem with CAF and where water is the superior agent for fire control.


Knowledge and Belief

As I have followed and occasionally participated in this discussion about CAF and water, I began to think about why we believe what we do (and the difference between belief and knowledge). Some of us are zealots who are fanatically committed to a particular perspective. In this case, belief does not require evidence (or evidence is seen through a lens that supports existing belief and all else is dismisses or disregarded). Some of us are skeptics who instinctively doubt, question, or disagree with generally accepted conclusions. Some of us accept information provided from sources that we consider authoritative, while others think critically, weighing evidence in deciding if a claim is always true, sometimes true, partially true, or false regardless of the source.

Historical Perspective

It is interesting that the fire service in the 21st century is engaged in a concerted effort to integrate theory and practice, research with the fire service conducted by Underwriters Laboratories (UL), National Institute of Standards and Technology (NIST) as well as universities, government agencies, and fire services from around the world. We continue to struggle with moving from practical knowledge based on observation and information passed from earlier generations of firefighters to evidence based practice where practical decisions are made based on research that is valid and reliable. There may be some lessons in the 19th century writing of Massey Shaw, the first Chief Fire Officer of the Metropolitan London Fire Brigade:

In a new profession, all measures are necessarily in some degree tentative. It is only the superficial and half-educated who, in such cases, announce everything in detail beforehand, and thus find themselves, for years afterwards, working in a false position, endeavoring, contrary to experience and their improved information, to justify announcements made by them while laboring under that most unsatisfactory, but perhaps most common, form of ignorance, which consists of practical knowledge, absolutely alone, without the aid of theory, and which is consequently to a great extent antagonistic to all useful developments.

To those who have not studied the principles of true and useful progress, this statement may seem a paradox, but it really is nothing of the kind. Theoretical knowledge is essentially progressive; it suggests new modes of doing everything; and, even where absolutely new odes are proved to be impracticable, it suggests modifications and alterations of existing modes, an devises schemes for meeting every possible objection which can be urged. Practical knowledge alone, unaided by theory, is, on the contrary, from its very nature, obstructive to the last degree’ it makes objections to everything not actually proved to demonstration, and, in short, considers nothing possible that has not been already accomplished. Then there are the innumerable imperfect combinations of theory and practice, which, as long as they remain imperfect, produce the worse consequences of all.

How often do we see a man, eminently practical in all respects, and whose opinion on any practical matter connected with his ordinary business is worthy of the highest consideration, suddenly seized with an idea, which, being unaided by education, develops itself into a theory of the wildest kind, involving those who follow it in utter ruin – and all because the supposed theory turns out to be no true theory at all, and nothing better than the excrescence of an uneducated or eccentric intellect. And again, how often do we see theory along, however sound in itself, utterly prostrate and rendered worthless, through flying too wildly for want of the obstructive and steadying power of practice (Shaw, 1868, vii)

Moving Beyond Simple Experience

Kurt Lewin, a social psychologist observed “There is nothing so practical as a good theory” (Lewin, 1951, p. 169). He expands on this idea, observing that theory makes it possible to move beyond simple collection and description of facts by characterizing what is behind those observations. Theory helps us make sense of practical experience.

As firefighters and fire officers in the 21st century, we need to move beyond simple experience and integrate a sound understanding of the theory of fire dynamics and fire control. Similarly, we need to be wary of theory alone, and integrate practical experience with scientific research and underlying theoretical concepts. Both are necessary, but neither is sufficient.

Be curious, think critically, and learn continuously!


Lewin, K. (1951). Field theory in social science. New York: Harper Brothers.

Shaw, M. (1868) Fire protection: A complete manual of the organization, machinery, discipline, and general working of the fire brigade of London. London: Charles and Edwin Layton

Tags: , ,

2 Responses to “Theory and Practice”

  1. Anthony Correia Says:

    My recent blog post has the se theme. More and more of us are getting. However many will go to the grave never accepting. Reality.

  2. Lars Says:

    Great post as usual Ed!

    I struggle as many do with my own predispositions.
    It is hard to Not believe what you believe, that is what it takes to change your mind. To stop believing in something you held for truth.
    And it is hard to disbelieve your own senses and experiences, that is also something you have to do in some cases.

    “I do not believe in climate change because last winter was cold!” is Not a valid argument when science tells you otherwise. Your opinion is no longer valid in the matter and you have to trust authority when overwhelming figures tells you otherwise.

    When science says something (not your backyard voodoo…) you better listen. It may not be the truth, but you better listen. Your own senses are not enough to judge effects when fighting fire, what you see, feel and hear (in other words you experience) is prone to errors. And even if you had super senses you would still have problems interpreting them because of our limited knowledge and predispositions.

    Be critical to your own experiences and to others experiences. Also be critical to science which Try to eliminate those errors but also struggle with the same problems.

Leave a Reply