The chapter provides a novel account of perceptual discrimination (krinein) in Aristotle. Against the widespread view that the most basic perceptual acts consist in noticing differences between two or more perceived qualities, I argue that discrimination is for Aristotle more like sifting, winnowing on a sieve: it consists in identifying – with an ultimate authority – the quality of an external object as distinct from any other quality of the given range that the object could have. The chapter further explores how the notion of discrimination is embedded by Aristotle within his causal assimilation model of perception. I argue that the central notion of a discriminative mean (mesotēs), introduced in An. 2.11, is intended to capture the role of the perceptive soul as the controlling factor of a homeostatic mechanism underlying perception. As such the notion lays the groundwork for resolving the apparent conflict between the passivity of perception and the impassivity of the soul (as analysed in Chapter 5). The prospect is further explored in Chapter 7. The present chapter concludes by arguing that Aristotle conceives perceptual discrimination as a holistic assessment of the external object acting on the perceiver, including those of its features which are not causally efficacious.

The chapter spells out the homeostatic model of how the soul is involved in perception introduced in Chapter 6, while addressing two main challenges for it. First, I argue that while the physiological details are not easy to tease out, there is no principal reason against Aristotle’s extension of the model from touch to other sense modalities. More importantly, I argue that we can understand the role of the perceptive soul as an extension of the model developed for the nutritive soul in An. 2.4 and based on Aristotle’s art analogy (from Phys. 2 and elsewhere). The upshot is that the basic perceptual acts are underlaid by bodily processes non-cognitively controlled by the soul. But while homeostasis is the aim of nutrition, in perception it only becomes a means for achieving something else, namely discrimination. The chapter closes by showing how the interpretation developed in this book pays off when it comes to understanding Aristotle’s two notoriously difficult concluding accounts: the account of perception as a reception of forms without the matter in An. 2.12 and the summarizing account of the cognitive soul in An. 3.8.

The addiction syndrome is quite similar across different addictive drug types, reflecting a shared pathway of pathological changes within motivational circuits that increasingly prioritize drug acquisition and use. This neurobiology, and drug addiction symptomatology, overlaps considerably with behavioral addictions (e.g., gambling disorder). However, addiction is distinct from symptoms and mechanisms underpinning intoxication and withdrawal, which are diverse and unique to each drug class. The intoxication phase is followed by some degree of withdrawal, manifesting clinically as opposite to intoxication, reflecting a homeostatic response to it. Withdrawal has a quality, duration, and dangerousness that depends on the individual, the drug type, and drug use history. Heavy/chronic patterns of use in addiction can produce longer, more severe withdrawal phases, but addiction and withdrawal can exist separately. How a drug acts upon different receptors and other downstream brain systems (pharmacodynamics) impacts the strength of its psychoactive (intoxicating) and motivational (addictive effects). Meanwhile, the route and rate of drug intake and its breakdown and elimination (pharmacokinetics) can also impact intoxication, withdrawal, and addiction risk. With addiction, the patient becomes tolerant (insensitive) to the intoxicating profiles of drugs they like, whereas their motivation, craving, and wanting to use the drug sensitizes (grows pathologically).

Renal function plays a key role in the body homeostasis as well as perioperative management of fluids. This chapter discusses the renal system anatomy and physiology as well as various metabolic disturbances of electrolytes including potassium, sodium, calcium, and magnesium.

The brain does not passively register sensory input but actively predicts it. The activity of the sensory input is ‘explained away’ and only activity that was not predicted remains. This remaining activity is treated as an error signal that is used to update the predictive coding system. Learning is predictive coding.

Stress causes brain damage. Unrelenting stress is an essential feature of legal education and legal practice, and chronic stress hurts the brain. Lawyers suffer from higher rates of anxiety and depression than the rest of the population and they rank fourth in professions with the highest number of suicides. Lawyers’ anxiety, depression, and suicide rates are likely linked to overwork and exposure to toxic chronic stress. Anxiety and depression can cause changes in the brain that are related to an overactive fight-or-flight stress response system. Lawyer languishing, a state of incomplete mental health, may be a precursor to lawyer’s anxiety or depression. The rat-fumbling researcher Hans Seyle noticed that the discomfort his lab rats suffered made them sick. He used the term stress to describe the general unpleasantness his rats experienced when he routinely dropped, chased, and recaptured them during his experiments. The culture of his lab was making his rats sick. When law school or legal practice cultures subject students or lawyers to a broad array of incessant stressors; the general unpleasantness is prone to make them physically and emotionally sick; and it damages their brain.

This chapter introduces our stress response system and how it works in the sprints of life. Under the best of circumstances and when we are in the pink of health, our stress response system functions like a finely conducted orchestra, and we hardly notice what a marvel of orchestration we live by. Herbert Benson’s studies in the 1970’s of the physiology of transcendental meditation paved the way for the Mind Body Institute and others to practice approaches retraining dysregulated stress responses. A discussion of the distinguishing features of our stress response system leads the concept of allostasis or the cumulative burden of stressors across a lifetime—a measure of the wear and tear of life.

This chapter discusses the direct effects of racial discrimination on Black Americans’ health. It begins by documenting that daily exposure to the various forms of racial discrimination is a common experience for Black people living in the United States. Encountering racial discrimination creates stress, which activates physiological stress responses – bodily systems that normally provide person with the energy needed to rapidly reduce the stress. However, the stress created by racial discrimination is usually chronic because many Black Americans repeatedly experience racial discrimination over a prolonged period of time. When the bodily systems activated by stress response remain active, it creates a harmful physical condition – allostatic overload. Allostatic overload is responsible for a host of physical illnesses, including heart diseases, diabetes, and immune disorders. It is also associated with poorer mental health, as well as alterations in epigenetics, such as premature aging. Chronic stress can also cause people to engage in behaviors that may provide short-term emotional relief from discrimination-related stress but are unhealthy, such as drug use or eating certain unhealthy “comfort” foods. In sum, prolonged exposure to racial discrimination is a chronic stressor that threatens the health of Black Americans.

The introduction briefly summarizes the contrasts between traditional views about mind and communication, including the computer and code metaphors.It summarizes the central perspective of the book, that human communication is embodied in a biological sense, as well as in a social and cultural sense, and briefly explains the meaning of these terms. It presents a case for conceptual clarity as a basis for critiquing conventional terminology based on computer and code metaphors, and proposes a more direct and accurate set of terms.

Chapter 2 introduces and explains the concept of homeostasis, and other concepts central to the evolution of the neural system, brain, and signaling.It describes key communication-related features of the evolving brain and contrasts them with digital computers as a basis for criticizing the computer metaphor and associated terminology.It introduces crucial concepts, including theory of mind, identity, and consciousness.

The correspondence commences in the summer of 1970, when a still untenured Margulis sends Lovelock a request for information along with offprints of her own work. The scientific collaboration of Lovelock and Margulis launched in earnest in January 1972, a year and a half after their first exchange of letters. The opening chapters of their correspondence document Margulis’s importance for both the construction and the communication of Gaian ideas. Their collaboration develops precisely as a writing partnership, with Margulis in the de facto role of in-house editor as well as co-author of their early papers. The letters exchanged in 1972 show them meticulously working through the host of technical matters intrinsic to their bold project until an initial manuscript is ready for submission. These early letters are also the most minutely specialized, as they are both still teaching the other what they need to learn in order to bring their respective specializations together.

The following chapter will address electrolyte abnormalities commonly encountered in the intensive care unit. Table 3.11.1.1 provides a general overview of the homeostatic mechanisms and the metabolism of the cations sodium, potassium, calcium and magnesium, as well as the anion phosphate. Table 3.11.1.2 provides a summary of the ECG changes that occur with various electrolyte abnormalities.