1 This review appeared as Review of Laura E. Weed, The Structure of Thinking. 2011. In Tradition and Discovery: The Polanyi Society Periodical XXXVIII(1):66-69. Laura E. Weed. The Structure of Thinking: A Process-oriented Account of Mind. Exeter, UK and Charlottesville, VA: Imprint Academic, 2003. Pp. 248. ISBN: 0907845274. $49.90. According to Weed, the human mind is not a computational device, and so efforts by those working in artificial intelligence to model the mind in this way are wrong from the fundamentals. In its stead, Weed proposes a model of human thinking as an essentially human product due to its interactive structure and unique relation to experience (see 6, 167). On this model, there are two different kinds of processes by which experience is organized and knowledge is generated. The first kind, Weed calls object-positing processes (or x-processes). Object-positing processes deal with a knower’s ability to recognize and identify particulars, with the ability to select temporally-bound singulars, with singular reference in language, and with other perception-based processes. The second kind of process, called property-attributing processes (or y-processes), deals with a knower’s ability to sort, qualify, and quantify particulars. In particular, it concerns the ability to formulate conditions for the conception of a stable object, the computational structuring of raw data obtained from perception, supplying the truth-conditions for sentences, and carrying out a variety of other computational procedures. Weed insists that both of these processes are needed to give a comprehensive model of human cognition, and so Weed’s The Structure of Thinking aims at showing that (1) x-processes cannot be reduced to y-processes, (2) y-processes cannot be reduced to x-processes, and (3) the human mind consists of both of these processes interacting with each other and the environment. While Weed does not take her claims to be decisive (216), she presents a variety of arguments, each aiming at shoring up the conceptual independence of object-positing and property- attributing processes. The primary opposition to her position is the attempt to reduce experiential, object-positing processes to conceptual, property-attributing processes (what she and others have called “Platonism in 20 th century analytic philosophy”). According to Weed, the latter reduction serves to undergird the view that the human mind is a computational device. Her major critique of 20 th century Platonists is that they “chase a third man” (see 8, 10, 18, 20). Weed writes, If … one starts one’s inquiry with questions about knowledge, such as ‘What do we know?’ or ‘What can be known?’, the natural answers to these questions seem to be ‘properties’ or ‘universals’. Plato and Berkeley both start their investigations with epistemological questions, and both ultimately have trouble with particular, material objects. For, once the properties and universals have been established as prior, objects become reducible to sets of properties. The third man argument exhibits the chief weakness of a property-oriented account of the nature of the world. Properties and relations are too variable to rate as the basic content of a recalcitrantly solid reality (8). What Weed means by “chasing a third man” is not clearly explained, but the gist seems to be the following: the reduction of an object of thought to a set of properties leads to an infinite regress since the set of properties is also an object of thought, requiring an explanation in terms of another set of properties, and so on, ad infinitum. According to Weed, this sort of Platonism has its claws in a variety of different philosophical concepts (causation, stable objects, and existence), and a large part of The Structure of Thinking aims at replacing these concepts with ones that are sensitive to the need for both object-positing and