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I have struggled with this one a bit.

From OPAR: "Consciousness, to repeat, is the faculty of perceiving that which exists. ('Perceiving' is used here in the widest sense, equivalent to 'being aware of.') To be conscious is to be consious of something." (pg 5-6)

Does this include plants which only have the faculty of sensation and not perception?

asked Nov 04 '10 at 11:49

T_K's gravatar image


Are you thinking of how plants react to light with their direction of growth, for example? I don't know the details of the biological process, but I think that's a chemical reaction. Plants don't have sense organs or an equivalent so as to have a faculty of sensation, which would be a form of consciousness.

(Nov 04 '10 at 14:09) BMV ♦ BMV's gravatar image

Let me expand a bit. I am trying to fully conceptualize what consciousness is, that's why I ask...

Pg 52 OPAR: "The fist stage of consciousness is that of sensation. A 'sensation' is an irreducible state of awareness produced by the action of a stimulus on a sense organ. 'Irreducible' here means: incapable of being analyzed into simpler conscious units. By its nature, a sensation lasts only as long as the stimulus. When light waves strike the retina, for instance, they produce a sensation of color; when the light is removed, the sensation disappears."

(Nov 05 '10 at 21:03) T_K T_K's gravatar image

I can see two ways to read this: 1) Anything that is alive and reacts to stimulus (i.e. a plant growing towards sunlight) has consciousness; or 2) the organism requires 'sense organs' (whatever those are defined as). This is my confusion.

Obviously rocks don't have consciousness, but it seems that plants would since they have a standard of value that is their life.

(Nov 05 '10 at 21:06) T_K T_K's gravatar image

I'm not sure why you think being alive, or having a standard of value, implies consciousness. Merely reacting to a stimulus is not consciousness. Consciousness is awareness of reality.

(Nov 05 '10 at 22:32) jasoncrawford ♦ jasoncrawford's gravatar image
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Plants aren't conscious. They lack sense organs and a nervous system. But the exact dividing line between reactivity in certain plants and primitive animal consciousness is a difficult and intriguing subject. The Venus Fly Trap is one of only a few species that is capable of rapid movement. The closing of the trap is stimulated by triggering of small hairs within the "trap," and it takes two triggers within a certain time to bring about the reaction. That reaction is not fully understood, but it involves an electrical process much like a single nerve action.

answered Nov 07 '10 at 18:34

Mindy%20Newton's gravatar image

Mindy Newton ♦

I don't think plants even have sensation. Plants aren't conscious at all; only animals are.

answered Nov 05 '10 at 02:22

jasoncrawford's gravatar image

jasoncrawford ♦

The methodology of this question is to take something that looks like a definition of consciousness, apply it to plants, and conclude that plants seem to fit the definition on at least a very rudimentary level. But where does the apparent definition of consciousness come from under that methodology? How could one ever reach such a definition?

The methodology of Objectivism, in contrast, is to look at reality, i.e., at existence, and observe that entities are the primary existents, that entities are of two types -- living and non-living -- that living entities are of two types -- plants and animals -- and that animals exhibit a type of awareness of existence that differs greatly from anything found in plants (even for venus fly traps). The concept "consciousness," then, is adopted to refer to animal awareness. (Side note: with the aid of modern biology, we can also identify that micro-organisms exist and that they, too, seem to fall into two distinct categories according to whether they are more plant-like or more animal-like.)

"Animal awareness" is not a definition of consciousness, however. To describe consciousness as "animal awareness" is to engage in circularity, for what is "awareness" but just another term for the same phenomenon that "consciousness" denotes. Objectivism recognizes that certain concepts -- existence, consciousness, identity -- are so fundamental, inescapable, and implicit in all knowledge that they are not definable in terms of other concepts. The only way to grasp and communicate what such concepts mean is to point to examples of them, and point out that they are everywhere (implicit in all knowledge). We use the term "axiomatic concepts" to refer to the extremely small number of concepts that fall into this category. When we point to examples of consciousness, we point to an attribute of animals (including man), not of plants. Plants can't match the attribute of consciousness that is found in animals.

For additional insights on the sensory level of consciousness, refer to "Sensations" in The Ayn Rand Lexicon. That collection of excerpts also provides an introductory discussion of the perceptual level of consciousness.


In a follow-up comment, the questioner stated: "I am trying to fully conceptualize what consciousness is, that's why I ask."

How does one "fully conceptualize what consciousness is?" Does one try to do it, for example, by studying the detailed causal mechanisms and processes that produce a metabolic and/or growth response in plants, and a sensory response in animals? Does one first study animals specifically, and then notice some similarities to plants, leading to the suggestion that perhaps plants are "conscious" in some way? I see that suggestion, if intended, as stretching the meaning of "consciousness" beyond all philosophically legitimate bounds and wreaking havoc on further scientific inquiry.

There was a four-part article in The Objectivist, Feb. to May, 1968, titled "Biology without Consciousness -- And Its Consequences," which traces exactly the way biological reductionism has led many to doubt whether consciousness truly exists at all, or has any objective meaning, or is unique to animals. Part I explains:

The science of biology suffers from a progressive and potentially fatal epistemological disorder. It is characterized by such profound chaos in the realm of definitions and the logical relationships between concepts that those who suffer from it have lost cognitive contact with reality. One of the most fundamental causes of this disorder is a philosophical principle: It holds that all the phenomena of life will ultimately be reduced to -- that is, accounted for, described by, and deduced from -- the laws of physics and chemistry. It is known as the "principle of reduction."

The result of blind adherence to this principle as been an intellectual smashup in neurophysiology and psychology.

If biological reductionism is implicitly involved in this question about consciousness and plants, it should be brought out into the open and addressed directly.

answered Nov 06 '10 at 02:37

Ideas%20for%20Life's gravatar image

Ideas for Life ♦

edited Nov 07 '10 at 01:47

While it is entirely true that consciousness is known axiomatically, not needing philosophical proof, the questioner is concerned with the scientific facts about consciousness. Recognizing that plants react to the same energies that in animals are sensory is a worthy observation. A fully adequate answer would be too lengthy, but the basic distinction between receiving and reacting to, let's say light energy as a plant does, and receiving and reacting to it as vision does is that the light drives, if the plant is healthy, a specific metabolic process, the plant's chief "business" of growth, repair, and reproduction. The specialized sense organs transduce (change its form) sensory energy so that it can be sustained (propagation) and combined with other sensory events (integrated )and eventually routed to end-points: actions. The sun's energy may be stored through chemical processes, but its role is limited to metabolic processes. Sensory energy brings about effects that continue as stimuli and potentially contribute to, or result in nerve-mediated action

answered Nov 07 '10 at 16:49

Mindy%20Newton's gravatar image

Mindy Newton ♦

edited Nov 08 '10 at 20:41

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Asked: Nov 04 '10 at 11:49

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Last updated: May 13 '11 at 15:51