What constitutes life is generally recognized to be: awareness, a vibrant body, and autonomous activity. Beyond that, an agreed-upon definition of life has proved elusive.
Life is the result of a special combination of atoms characterized by their constant mechanical movement. ~ Democritus
4th-century-bce Greek rationalist philosopher Democritus was a strict determinist and a matterist: believing that everything accorded with natural laws. Chance had no chance.
Democritus thought that life was maintained by the inhalation of fresh atoms, replacing those lost by exhalation. When respiration ceases, atomic recycling stops. The result: death.
Further, Democritus believed that humans, and humans alone, had a noble portion: the soul, pervading the body via psychic atoms. The soul, while distinct from the body, was material, and perished when the body died.
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Historically, there have been 3 schools of thought on what makes life special: matterism, hylomorphism, and vitalism. Another school, animism, discounts life as extraordinary.
Animism considers all objects and bodies, animate or otherwise, spiritually imbued; there is no meaningful separation between the material and metaphysical. Any perceptible entity possesses a spirit, including rocks, mountains, and rivers. Animism is not especially concerned with defining life, as all of Nature is holy.
Variants of animism form the core of various religions, including Hinduism, Buddhism, Shinto, Jainism, and other belief systems labeled pantheistic, where reality is identical with divinity. English anthropologist Edward Tylor called animism “one of anthropology’s earliest concepts, if not the first.”
Matterism, embraced by Democritus and revived by French philosopher René Descartes in the 17th century, makes life out to be a complex arrangement of materiality. To Descartes, soul was a matter of matter.
Aristotle, the ancient Greek master abstractor, concocted hylomorphism: that all things are a combination of matter and form. The form of life is in the soul.
Aristotle posited 3 kinds of souls: vegetative soul for plants, which could not move or experience sensation; animal soul, where moving and feeling are part of the package; and rational soul, found only in humans.
Aristotle believed the relationship between matter and soul is asymmetrical: matter can exist without form, but form cannot exist without matter. Therefore, the soul cannot exist without the body. Aristotle believed that purpose was the final cause of life.
Vitalism posits that living organisms possess a fundamental ingredient which distinguishes them from inanimate matter. The missing element is the spark of life, often equated with a soul.
The idea of vitalism is prehistoric. Ancient Egyptians wrote of vitalism. In the 3rd century, Greek anatomist Galen of Pergamon, the most accomplished medical researcher of antiquity, held that vital spirits were necessary for life.
In embracing the concept of souls for at least some life, vitalism underlies monotheist Western religions. Man’s dominion over the Earth is granted by The Bible. To merit this grant, Christian theologists quixotically posited the superiority of man as being sole possessor of a soul (women ever being an adjunctive afterthought). The revival of Aristotelian thought in the 12th century abetted the effort.
As science ushered in stricter empiricism during the Age of Enlightenment, vitalism lost its vitality. The spark of life was lost – replaced by faith in reductionist chemistry, wherein life was merely a peculiar molecular combination in a grand cosmic machine.
There is no special force exclusively the property of living matter which may be called a vital force. ~ Jöns Jacob Berzelius in 1836
Not all were convinced.
18th-century French physiologist Xavier Bichat is remembered as the father of modern histology and pathology. Working without a microscope, his insights are especially remarkable. Bichat introduced the notion of tissues, and maintained that diseases attacked tissues, not whole organs. Bichat also believed that life held “vital properties” beyond its material constituents.
The organizing principle, which, according to an eternal law, creates the different essential organs of the body, and animates them, is not itself seated in one particular organ. ~ Johannes Peter Müller
German physiologist Johannes Peter Müller penned his magnum opus – Elements of Physiology – between 1833 and 1840. For the first time, Müller exposited an integration of chemistry, microscopic investigation, and comparative anatomy as approaches for studying physiology.
An important facet of Müller’s study was how the senses work and are employed. Müller’s detailed explanations had an overarching theme: the presence of a soul renders each organism vibrantly whole. He claimed that the perception of sound and light waves demonstrated that living organisms held a life-energy for which physical laws could never fully account.
Following in Müller’s footsteps, 19th-century French chemist and microbiologist Louis Pasteur believed that living organisms possessed “irreducibly vital phenomena.”
One fact about vitalism is irrefutable: empirical science has no explanation for how life is even possible.
Before the time of Darwin, it was usually assumed that the behavior of animals was under the control of blind instinct. This was flattering to man, who prided himself on his possession of reason. ~ English zoologist David McFarland
The essential activity of life is staying alive. All life behaves. Behaviors arise from decisions. Decisions derive from discernment.
Life requires cognition at all levels. ~ American molecular biologist James Shapiro
Reason or intelligence is the faculty which is concerned with the intentional adaptation of means to ends. ~ Canadian Scot evolutionary biologist George Romanes in 1892
Staying alive requires intelligence: gathering information and making sense of it, to act with will. At root, the intelligence of all life is selfsame: managing the concepts that come with perception, problem-solving, and decision-making.
(The process of intelligence is gathering and analyzing information. The relative measure of intelligence is the ability to behave appropriately.)
The subject of the earliest cognition was electrochemical: reacting differently to distinguished chemical compounds. This makes perfect sense when considering that chemistry begat biology; that life originated via sequences of consistent chemical reactions, and that cells sustain themselves via cogent memory of requisite reaction sets. Memory is a sketch of experienced events, but, more specifically, the comprehension derived from those events.
Beside responding to the environment, organisms must proactively initiate chemical reactions and do so at an appropriate time. That takes intelligence, which is based upon memory.
Memory may be transferred from one generation to the next. Such inter-generational remembrance is called instinct.
Intelligence is exhibited by appropriate behavior. Appropriateness is a discrimination based upon available information.
Forging reactions to create or break down compounds requires recognition that all the necessary ingredients are available, including energy, as well as having an orderly way to manage the process, and deal with the outcomes, including waste. The forgoing applies to all craft work, from a single cell to a woman in a workshop.
Cell evolution has been a process of increasing sophistication in intelligence: augmenting reaction sets, as well as building layer upon layer of complexity in compounds and sequence sets, all of which must be remembered; whence the artifacts of accumulative genetics and the sophistication of proteins.
Intelligence stems from sensation, which provides a running chronology of events. Sensory awareness necessitates consciousness.
Consciousness inhabits every organic structure that must act with discretion. Every organism and every cell within has a mind which experiences sensations and processes them into perceptions, which are mental symbolic representations with assigned meanings.
Microbes, fungi, protists, and plants are all intelligently resourceful despite having no discernable intelligence physiology. Physical intelligence systems – such as the brains and nerve networks in some animals – are simply artifacts for invisible sentient energy gyres.
Memory relates what worked in the past. Current intel tells what might work in the present. Every behavioral choice is based on information.
The term intelligence descends from the Latin word interlegere: to choose between. Implicit is assessing information as a basis for choice.
Modern dictionaries define intelligence as the ability to understand. It is an inapt definition. Intelligence can only be assessed by observing behavior. So, defining intelligence as comprehension, however accurate, is a non-starter from a practical perspective.
The adaptiveness of behavior is one of the most dominant features that we observe. Of course, animals do make mistakes and may appear clumsy at times, but for the most part their behavior is beautifully matched to their way of life. They respond appropriately to the features of their world and thereby feed themselves, find shelter, mate, and produce offspring. ~ English zoologist Aubrey Manning & English ethologist Marian Stamp Dawkins
Outcome, not behavior itself, provides the basis for assessing sagacity. The concept of outcome is a slippery one, in having a temporal context which may echo.
Behavior may set into motion a gyre of events whereupon immediate result presages a much different aftermath in terms of affecting the well-being of the organism that performed the behavior. An initially positive outcome may transform into disaster. Consider human civilization, and the extinction event it has created. Much-vaunted technology has proven a curse for sustainability.
A usable definition of intelligence emerges as: regular behavioral outcomes that confer survival advantage.
Intelligent behavior has to be judged within the structural constraints. ~ English botanist Anthony Trewavas
In defining life, one might be tempted to add that an organism is self-contained – that is a constricted view. Living is an ecological exercise: entangled interactivity between an organism and its habitat. Life is a process, not a body. An organism is a gyre of activity: a being. In sum, life is vigorous intelligence, existing in a form that is ecologically active.
The evolution of cells aimed at functional optimization which spelt specialization: one part of a cell does something, while another does something else. Intracellular actions must be coordinated. Coordination requires communication.