Lamarck's Principles

In order to give the idea of species has some real foundation, let us look at following points:

1. All organic bodies of our earth are true products of nature, which she has brought forth successively over a long period of time;

2. In her progress, nature began, and begins again every day, by creating the simplest organic bodies

She does not directly create anything except by this process of first beginnings of organic structure.

• These are spontaneous generation.

3. The first beginnings of animals and plants were formed in appropriate places and circumstances.

Once the faculties of a commencing life and of organic movement were established, these animals and plants of necessity gradually developed organs.

In time, they diversified these organs, as well as their parts.

4. The faculty of growth in each portion of an organic body is inherent in the first effects of life

It gave rise to different ways of multiplication and reproduction of individuals.

In this process, the progress acquired in the composition of the organic structure and in the shape and diversity of parts was maintained.

5. In time, through favourable circumstances, new habits modified the organs of a body.

6. After a sequence of events, living bodies experience changes in their organic structure

What we call species have been created in this way imperceptibly and successively.

They have a constancy which is only relative to their condition and cannot be as old as nature.

A long time and an infinite variation in circumstances, nature has gradually formed the animals we know.

Some think that the diversity in the instincts of these animals debunks this theory.

Nature herself brings about all these wonders.

She has created organic structures, life, even feeling.

she has multiplied and diversified within unknown limits the organs and faculties of organic bodies that she supports

she has created in animals, by the sole route of needs, which establish and direct habits, the source of all actions, all faculties, from the simplest right up to those which make up instinct, work,

this power of nature is in the order of existing things

It shows the will of her divine Author

Will I admire less the grandeur of the power of this first cause of everything if it has pleased Him that things were like this, that if, by so many acts of His will, this power was occupied and still is continually occupied with the details of all the particular things of creation, all the variations, all the developments and improvements, all the destruction and all the renewals, in a word, of all the transformations which universally happen in existing things?

I will prove that nature can produce by herself what we admire in her.

However, another objection is that everything which we see announces an unalterable constancy in the conservation of form in living things.

All the animals that we have known in the past 3,000 years:

• have always been the same
• have lost nothing
• have acquired nothing in the improvement of their organs and in the shape of their parts.

To prove this apparent stability over a long time as a verified fact, the Report On the Collections of Natural History Brought Back from Egypt by M. Geoffroy writes:

Geoffroy

People have wanted to know if species change their form through time.

The superstition of the ancient Egyptians was inspired by nature, with a view to leaving a monument of her history.

As a result of this part of Geoffroy’s collection, these animals are perfectly similar to today’s."

Annales du Muséum d’Hist. natur., vol. I, p. 235, and 236.

I do not deny the conformity in the appearance of these animals with individuals of the same species alive today.

Thus, the birds which the Egyptians adored and embalmed 3,000 years ago are still totally similar to those alive today in Egypt.

This is because the past situation of Egypt and its climate are still similar to today.

This apparent stability of things in nature will always be taken by common opinion as the truth of things, because, in general, people do not judge anything except in relation to themselves.

The man who judges only according to changes which he perceives himself, the intervals between these mutations are conditions of stability which appear unlimited to him, because of the brevity of the lifetime of the individuals in his species.

His observations and factual notes go back only a few thousand years which is long compared with him.

• But it is extremely small compared to great changes in the Earth.

Quantities of space and time are relative.

In acknowledging the imperceptible changes in species and the modification which individuals undergo, to the extent that they are forced to vary their habits or to acquire new ones, we are not confined solely to a consideration of the very small extents of time which our observations can include to allow us to see these changes.