Jean Piaget

Scientific thought, then, is not momentary; it is not a static instance; it is a process.

On the one hand, there are individual actions such as throwing, pushing, touching, rubbing. It is these individual actions that give rise most of the time to abstraction from objects.

Logical positivists have never taken psychology into account in their epistemology, but they affirm that logical beings and mathematical beings are nothing but linguistic structures.

I have always detested any departure from reality, an attitude which I relate to my mother's poor mental health.

The principle goal of education in the schools should be creating men and women who are capable of doing new things, not simply repeating what other generations have done.

To express the same idea in still another way, I think that human knowledge is essentially active.

The child of three or four is saturated with adult rules. His universe is dominated by the idea that things are as they ought to be, that everyone's actions conform to laws that are both physical and moral - in a word, that there is a Universal Order.

It is with children that we have the best chance of studying the development of logical knowledge, mathematical knowledge, physical knowledge, and so forth.

During the earliest stages the child perceives things like a solipsist who is unaware of himself as subject and is familiar only with his own actions.

The child often sees only what he already knows. He projects the whole of his verbal thought into things. He sees mountains as built by men, rivers as dug out with spades, the sun and moon as following us on our walks.

Every acquisition of accommodation becomes material for assimilation, but assimilation always resists new accommodations.

The first type of abstraction from objects I shall refer to as simple abstraction, but the second type I shall call reflective abstraction, using this term in a double sense.

Intelligence is what you use when you don't know what to do: when neither innateness nor learning has prepared you for the particular situation.

Knowing reality means constructing systems of transformations that correspond, more or less adequately, to reality.

Play is the work of childhood.

The current state of knowledge is a moment in history, changing just as rapidly as the state of knowledge in the past has ever changed and, in many instances, more rapidly.

The goal of education is not to increase the amount of knowledge but to create the possibilities for a child to invent and discover, to create men who are capable of doing new things.

Logic and mathematics are nothing but specialised linguistic structures.

Our problem, from the point of view of psychology and from the point of view of genetic epistemology, is to explain how the transition is made from a lower level of knowledge to a level that is judged to be higher.

Equilibrium is the profoundest tendency of all human activity.

Moral autonomy appears when the mind regards as necessary an ideal that is independent of all external pressures.

In genetic epistemology, as in developmental psychology, too, there is never an absolute beginning.

The main functions of intelligence, that of inventing solutions and that of verifying them, do not necessarily involve one another. The first partakes of imagination; the second alone is properly logical.

This means that no single logic is strong enough to support the total construction of human knowledge.

Punishment renders autonomy of conscience impossible.

One of the most striking things one finds about the child under 7-8 is his extreme assurance on all subjects.

In other words, knowledge of the external world begins with an immediate utilisation of things, whereas knowledge of self is stopped by this purely practical and utilitarian contact.

Logical activity is not the whole of intelligence. One can be intelligent without being particularly logical.

Everyone knows that at the age of 11-12, children have a marked impulse to form themselves into groups and that the respect paid to the rules and regulations of their play constitutes an important feature of this social life.

Scientific knowledge is in perpetual evolution; it finds itself changed from one day to the next.

The self thus becomes aware of itself, at least in its practical action, and discovers itself as a cause among other causes and as an object subject to the same laws as other objects.

The more the schemata are differentiated, the smaller the gap between the new and the familiar becomes, so that novelty, instead of constituting an annoyance avoided by the subject, becomes a problem and invites searching.

Reflective abstraction, however, is based not on individual actions but on coordinated actions.

From this time on, the universe is built up into an aggregate of permanent objects connected by causal relations that are independent of the subject and are placed in objective space and time.