Active causation and the origin of meaning

Abstract

Purpose and meaning are necessary concepts for understanding mind and culture, but appear to be absent from the physical world and are not part of the explanatory framework of the natural sciences. Understanding how meaning (in the broad sense of the term) could arise from a physical world has proven to be a tough problem. The basic scheme of Darwinian evolution produces adaptations that only represent apparent (“as if”) goals and meaning. Here I use evolutionary models to show that a slight, evolvable extension of the basic scheme is sufficient to produce genuine goals. The extension, targeted modulation of mutation rate, is known to be generally present in biological cells and gives rise to two phenomena that are absent from the non-living world: intrinsic meaning and the ability to initiate goal-directed chains of causation (active causation). The extended scheme accomplishes this by utilizing randomness modulated by a feedback loop that is itself regulated by evolutionary pressure. The mechanism can be extended to behavioural variability as well and thus shows how freedom of behaviour is possible. A further extension to communication suggests that the active exchange of intrinsic meaning between organisms may be the origin of consciousness, which in combination with active causation can provide a physical basis for the phenomenon of free will.

Appendix: Terminology

Several of the terms used in this article, such as “meaning”, “active”, and “freedom” are veterans of natural language for describing human affairs, and they are therefore, as common in natural language, somewhat broad, vague, and ambiguous. In this section I will try to explain a bit more accurately than in the main text as to how I use them, in order to reduce their ambiguity within the present context.

The main point of this article is that an internalized fitness estimate, $\hat{f}$, is used in feedback loops as in Figs. 1c and 3a for modulating hereditary and behavioural variability. This estimate and its form represent what is designated by the term “intrinsic meaning”. This use of the word “meaning” is close to that given by the Oxford English Dictionary (OED online, accessed May 22, 2014) as [meaning, n.2, 1], for example as used in expressions like the meaning of an action or the meaning of life. It implies significance, import, value, and purpose. Such a broad spectrum of denotations is appropriate here, because using $\hat{f}$ is presumably a feature of all forms of life (van Hateren 2013), and it represents at the same time a goal-directedness (as in life striving for high fitness in order to survive and reproduce), a value in the form of high fitness, and, through the form of $\hat{f}$ (i.e. of which parameters it is a function, and in what form) which aspects of the environment and itself the organism takes into account for estimating its own fitness. Those aspects are the ones that represent significance and import to the organism. For most organisms the goal-directedness is merely an implicit drive in the direction of appropriate, though underdetermined end-points (together producing high fitness). However, in organisms where $\hat{f}$ becomes so complicated and flexible that it gives rise to planned behaviour (Figs. 7, 9), consciousness, and language (van Hateren 2014), end-points may be produced by simulation or even conscious deliberation, and thus evolve into genuine purposes.

It is important to stress that “meaning” is used here not in the more narrow linguistic sense as in the meaning (signification) of a word [OED, meaning n.2, 2], and also not as a means for categorization and symbolic generalization. Nevertheless, it is likely that this more narrow sense can be understood as derivable from the broad sense, as the end result of an as yet not completely resolved chain of reasoning (sketched in van Hateren 2014). The term “intrinsic meaning” is also different from “value” in the sense of the variable defining a value-driven decision process: “intrinsic meaning” is not a single number, but includes the form of the estimated fitness function and the fact that there is an implicit drive towards high estimated fitness.

Apart from “intrinsic meaning”, the feedback loops of Figs. 1d and 3 also give rise to a special form of causation, because stochasticity is continually modulated by the goal-directedness of $\hat{f}$ and thus produces hereditary and behavioural trajectories that are unpredictable, but not random. This form of causation is designated by the term “active causation”, with the meaning of “active” close to that given in [OED, active, 2], i.e. capable of acting on something, originating action, spontaneous, voluntary. Active causation is contrasted with deterministic causation, which cannot originate anything new because systems subject to deterministic causation passively follow internal or external influences, like a clockwork. It is also contrasted with stochastic causation, which does originate new events and does so spontaneously (not caused by internal or external influences), but cannot be seen as producing action (because it lacks a goal-directedness) nor doing so voluntarily (because it lacks purpose). Both deterministic and stochastic causation are therefore designated by the term “passive causation” here, because either lacks several of the defining characteristics of “active”. The feedback loops of Figs. 1c and 3a entangle deterministic and stochastic causation in such a way that all defining characteristics of “active” are produced: there is the capability to originate and initiate in a spontaneous way (because of the stochasticity), but also in a way that can be seen as acting and performing action, because of the intrinsic goal-directedness produced by the feedback loops. For advanced organisms with reasoning and consciousness (van Hateren 2014), the acts can be deliberate and voluntary.

The ability to originate and perform action is a form of “freedom” for the organism, because its behaviour is neither dictated by a determined chain of causation, nor by the arbitrariness of randomness. This sense of freedom is close to [OED, freedom, 5], i.e. the power of self-determination (but without the mental or spiritual connotations), which can be seen as an absence of necessity [OED, necessity, 2], i.e. an absence of “constraint or compulsion having its basis in the natural order or constitution of things, esp. such constraint perceived as a law prevailing throughout the material universe and within the sphere of human action.”