(1) Evidence from everyday life. Such evidence is abundant and overwhelming—assuming one has enough wit to notice it. Oakeshott himself gives the example of the master chef and the cookbook. Let us assume that a master chef has made recipes of all his best dishes and put them in a cookbook. Would it be possible to duplicate the results of the master chef simply by following the recipes in the cookbook? No, of course not. If that were true, anyone could become a master chef merely by following the recipes of a master chef. It is widely recognized that in cookery, along with other complex endeavors, expertise is necessary. What qualifies one as an expert? Beyond a simple competence/intelligence, what is required is long experience within the given domain of experience in which one is an expert.
Another compelling example of practical knowledge is grammar. Consider what the sociologist Vilfredo Pareto has to contribute on the subject:
It would be absurd to claim that the theory of grammar preceded the practice of speech. It certainly followed, and human beings have created the most subtle grammatical structures without any [conscious, technical] knowledge of it. Take the Greek language as an example. We cannot imagine that the Greeks one day got together and decided what their system of conjugation was to be. Usage alone made such a masterpiece of the Greek verb. In Attic Greek there is the augment, which is the sign of the past in historical tenses; and, for a very subtle nuance, beside the syllabic augment, there is the temporal augment, which consists in a lengthening of the initial vowel. The conception of aorist, and its functions in syntax, are inventions that would do credit to the most expert logician. The large number of verbal forms and the exactness of their functions in syntax constitute a marvelous whole. [Mind and Society, §158]Grammatical knowledge is interesting precisely because it is developed in young children who could never have grasped it explicitly, through the means of articulated, formalized rules. The practical knowledge of grammar thus precedes the technical knowledge of this domain, which flies in the face of Rand's view of automatized knowledge, with its orientation toward the primacy of technical knowledge view.
(2) Evidence from Cognitive Science. but if the evidence from common experience is not sufficient to convince the incorrigible skeptic-rationalist, then we have evidence from cognitive science as well. Robin Hogarth has a very interesting article on intuition which draws heavily on cogsci research. Hogarth distinguishes two modes of judgment, the tacit (or intuitive) and the deliberative (analytical). These two modes are analogous, though not identical, to Oakeshott's practical and technical knowledge. (The main difference is that Hogarth's tacit knowledge is a wider conception that Oakeshott's practical knowledge—i.e., practical knowledge is a kind of tacit knowledge.)
Oakeshott claims that "practical knowledge can neither be taught nor learned, but only imparted and acquired." This suggests that practical knowledge is learned without us realizing how we learn it, that it is learned unconsciously. Hogarth's tacit knowledge is learned (in part) in a similar manner (i.e., unconsciously). According to Hogarth, "information about stimuli are recorded without conscious awareness and stored for possible future use. This very basic process is at the heart of tacit learning and the accumulation of facts and frequencies that has now been so well documented in the literature. It requires neither effort nor intention and, yet, the information stored can be subsequently recalled when needed, even for tasks we would have never imagined."
Oakeshott also insists that practical and technical knowledge work hand in hand. Hogarth buttresses this view by noting that "it is important to emphasize that in many cases the deliberate response will be influenced by the tacit response and all that precedes it. In other words, people will always have some tacit response (however minimal) to any triggering event."
Oakeshott also emphasizes the importance "connoisseurship" and mastership through experience—in other words, what cognitive scientists call "expertise." Here's what Hogarth has to contribute about expertise:
There have been many studies of expertise. From our perspective, there are several key findings. First, expertise is limited to domains and is only acquired through exposure to and activity within specific domains. Thus, because someone is an expert in one domain (e.g., chess) does not mean that she will be an expert in another domain (e.g., medicine) unless she has also had considerable experience in the latter. Second, outstanding performance in any domain takes years of dedication. Moreover, high performers have typically followed demanding regimes of deliberate practice and benefited from good teachers. Third, there is – curiously – less relation between expertise and predictive ability in many areas of activity than one might imagine. However, this finding may be more indicative of the nature of the uncertain environments in which experts operate than due to a lack of “expertise” per se. Consider, for example, the random nature of movements of the stock market. Fourth, experts and novices process information in different ways. Experts acquire habits that allow them to process more information than novices. They learn, for example, how to counteract limitations in short-term memory and to “chunk” information more effectively. They also use different problem-solving strategies. Novices tend first to identify a specific goal and then work backward through the details to determine a solution – making much use of deliberate thinking. Experts, on the other hand, rely more on tacit processes. They tend first to take in the details of the problems they face, and then determine (by recognizing patterns and similarities) a general framework that allows them to explore possible solutions. Not surprisingly, experts solve problems faster than novices.This pretty much matches Oakeshott's view, particularly the assertion that "experts acquire habits that allow them to process more information than novices." Such habits are precisely what Oakeshott is referring to when he talks about practical knowledge.
Hogarth has another interesting comment to make on tacit knowledge which could help explain its importance in human cognition. He notes that
Attention in consciousness is limited and therefore costly. In the framework, I assume a scarce resource principle. The key idea is that because the deliberate system consumes limited resources, it is used sparingly. It is allocated to tasks that are deemed important at given moments but can be switched to other tasks as the situation demands. It is rarely “shut down” completely and often has a monitoring function. In most cases, the tacit system is our “default” and the deliberate system is invoked when either the tacit system cannot solve the problem at hand or the organism is making some conscious decision (for example, planning what to do).
I would also note, in conclusion, what we have discovered in previous Cognitive Revolution posts: namely, that "unconscious thought is 95 percent of all thought" and that "nearly all important thinking takes place outside of consciousness and is not available on introspection." Hogarth's scarce resource principle helps explain this fact about the dominance of the unconscious in thought. Yet there is another principle which can be added to this that is part of my own theory. It is well known (even Rand admits) that conscious attention is limited: only so much can be attained in consciousness at any one given moment. The practical effect of this is that consciousness is not very well equipped to handle complexity. Since it is very difficult to hold in memory all the factors in a complex situation, the attempt to understand complexity through deliberate conscious reasoning easily breaks down. Hence I conjecture that unconscious thinking is required for human beings to grasp complexity and nuance. Since the unconscious has access to everything in the brain, included all memories, whether received consciously or not, it can form intuitive inferences that are cognitively far more powerful than what the mere conscious can do.
Any philosophy which, like Rand, glorifies and accentuates conscious deliberate thinking at the expense of originative unconscious intuition, vastly underestimates the cognitive capabilities of man's mind.