Section 4

The Plant Powers and the Need for Each of Them

September 27, 2022

Bodies with souls, if considered from the side of their vegetable powers, are found to have in common the getting of nourishment, and to differ in growth and generation (reproduction of offspring); since, among nourishment-taking beings, there are such as do not grow, for example a living individual that has reached full growth and the period of stand still, or that has declined therefrom through withering.

Yet every growing thing gets nourishment.

Again, among nutriment-taking beings there are such as do not propagate, as seeds that are not yet harvest-ripe, and an animal that has not yet reached puberty. Nevertheless, every propagating thing has inevitably passed through a preceding stage of nutrition; nor will the state (stage) of propagating ever be deprived of nutrition.

Further, we find them, beside having the getting of nourishment in common, to have growth also in common, but to differ in the propagation (of offspring) since there are, among growing things, such as do not beget, as an animal not yet arrived at puberty, and the worm.[11] Nevertheless every begetter has already passed through a period of growth; nor will the state (stage) of begetting be deprived of the power of giving growth [to the young that are being produced].

Hence there are 3 plant powers:

  1. The nutritive
  2. The growth promoting
  3. The propagating

Of these, the nutritive is as the starting-point

; the propagating as the aim and end

the growth-promoting as the means binding the end to the starting-place.

The souled body stands in absolute need of these 3 powers because:

The Divine Command came down upon Nature enjoining (imposing) upon her the task of forming a compound living being out of the 4 elements after such wise fashion as they called for in it.

Whereas Nature of herself is unable to originate a souled body at one stroke, but can do so only by promoting its growth little by little;[F] and whereas an individual that is put together after the manner of animal composition is susceptible of being again decomposed and melting away by the natures of its constituents

Whereas a thing composed of opposites will not keep up so protracted a duration and last so long a time as is expected of it.

Therefore, Nature is in want of a power by which she can fabricate a living body by promotion of growth.

So she has been supplied by Divine Providence with the growth-giving power; and is in want of a power whereby she can preserve the souled body at an even standard[G] over against the waste which it undergoes in making up for what disintegration wears away from it.

So she has been succoured by Divine Providence with the nutritive power; and is in want of a power that shall mould, out of the living natural body, a piece that she shall dwell in, in order that if corruption permeate the body it shall have sought for itself a successor as a substitute, whereby to arrive at the preservation of species; so she has been helped by the Divine Providence with the propagating (generating) power.

The growth-giving power follows close to the nutritive. The propagating (generating) follows close on the growth-imparting (promoting).

Yet the precedence of the part played by each 1 of the 3, in their undertaking the task of creating the living body and preserving it through their special and peculiar workings, is the other way about; for the first to enthrall the material predisposed to receive life is the generating (procreating, propagating) power, since this power clothes the material at first with the form (prototype) of that which is intended to be realized through the ministry (service) of the growth-promoting and nutritive powers;

As soon as it has achieved in that material a perfect form it delivers over the sway to the growth-promoting power, which assumes it through the ministry (service) of the nutritive power, and imparts to the material—all the time keeping up the form of the material within the due proportions of the [three] dimensions [length, breadth and thickness]—a motion (activity) of growth towards the end striven after by it, the growth-promoting power aforesaid.

Then this latter stops.

The nutritive power enthralls the material.

The generating (propagating) power is the one served, not the servant. In comparison with it, the nutritive power is the servant, not the one served.

Thus too the growth-promoting power is served in one sense, and serving in an other sense.

The nutritive power does not exist as the one served in the spiritual powers. Yet it does sometimes employ the 4 forces of Nature:

  1. The attracting
  2. The holding
  3. The digesting
  4. The excreting (repelling)

Even as that which is striven after in the process of form-making is solely the bringing about of the [due] form in matter in the shape (kind, design) proposed, and not at all the bringing about of growth or of nutrition,—only that there is need for the two latter for the sake of realizing the desired form, and not the converse—so also the final aim in the [several] powers is the procreating (propagating) power, to the exclusion of the growth-promoting and of the nutritive. Wherefore, the procreating power is given precedence for a teliological reason.


[11]Probably his view was that worms arise out of a germ of moist clay or mud, and are a sort of developed protoplasm. Compare §6 of Ibn Tufayl’s «Hayy b. Yaqzân,» and the Note thereto in the English Translation about field-rats.

[F]The germ of the Doctrine of Evolution as against Instantaneous Creation.

[G]See Ibn Sînâ’s «Qânûn,» Section 2, where he says: As to the nutritive power, it is that power which transforms the nutriment into a resemblance with the nourishment-taker, in order that this nutriment may succeed in the stead of what shall be wasted, and attach itself to the taker instead of the waste.—See also «Kitâb-ul-Najât,» by Ibn Sînâ.