It reads like a fable. Lev Vygotsky was born in pre-revolutionary Russia to a Jewish family, and died in 1934 aged 37. His short life was packed with enormous achievement.

You may not have heard of him, but he was possibly the most important educational mind of the 20th century. Yet it is now, in the 21st century, with pedagogical arguments raging on a global scale about how we teach and how children learn, that his ideas seem most extraordinarily prescient.

Recognised early as a brilliant scholar, Vygotsky won a place at Moscow university, where he read law. He developed an interest in psychology and, self-taught, gave a remarkably impressive paper at the Second All-Russian Psychoneurological Congress in Leningrad in 1924. He was invited to join the Institute of Psychology in Moscow as a research fellow, and there he devised a signing system for deaf-blind children that is now recognised as one of the most subtle and effective.

This was just the beginning, however. Teaching for more than five hours a day, he also ran a research team devoted to the development of a historical, cultural and psychological theory of the development of thought. Much of this work was explosive, but two years after Vygotsky’s death his book Thought and Language was suppressed by the Soviet authorities. The long silence was broken only in 1962, when scholars in Cambridge, Massachusetts, produced an English translation of the text.

Vygotsky’s work and thinking has extraordinary resonance today. With limited time and resources, he used his prodigious intelligence to “think big”. Educational research is bedevilled by small-scale studies giving answers to questions that most teachers never ask, yet even today Vygotsky’s legacy is a treasure trove for teachers from early years to university level.

His most important idea, and the basis for all his work, was that children do not act alone in their discovery of the world; they learn and develop within a society and a culture. He observed that children started school with “spontaneous concepts” learned through life experience, concepts such as: snow is cold; if you cut your skin you will bleed; price tags in shops show how much an item costs. He argued that a teacher’s core role was to take these “spontaneous” concepts and use them as a basis for building abstract (what he called “scientific”) concepts: snow is crystallised frozen water; blood flows through a cut because of the body’s circulation system; goods cost different amounts (which leads to understanding of the crucial mathematical concepts of “more” and “less”).

Vygotsky developed the idea of a “zone of proximal development”, which he defined as the brain space in which the child, with assistance from the teacher, has the potential to move from “spontaneous” to “scientific” concepts. “What a child can do in cooperation today, he can do alone tomorrow,” he wrote. “Therefore the only good instruction is that which marches ahead of development and leads it; it must be aimed not so much at the ripe as at the ripening functions.”

In other words, the best teaching focuses on the edge of a child’s understanding, taking them, with help, where they cannot go alone.

From thought to speech

Vygotsky’s most profoundly important theory was of the role that language plays in the development of thought. He took Piaget’s theory of egocentric speech (speech for oneself) in infants and radically transformed this concept. He set nursery children a task with an inbuilt difficulty - for example, children asked to draw a picture would find that there was no pen or paper - and discovered that in these situations the amount of egocentric speech doubled.

He concluded that egocentric speech is used by children to focus their thoughts; to hear themselves think, if you like. He observed that as children got older they would use egocentric speech earlier in their activity - they would pause and speak to themselves before they started to act, using speech to order thought and plan action.

Vygotsky noted that the transition from thought to speech is “no easy matter”. “A speaker often takes several minutes to disclose one thought,” he wrote. “In his mind the whole thought is present at once, but in speech it has to be developed successively. A thought may be compared to a cloud shedding a shower of words.”

So what are the implications of this theory of speech for today’s teachers? One central lesson is that a classroom where the teacher does nearly all the talking, and where students are limited to giving short answers to closed questions, is not an environment that develops young people’s ability to investigate, collaborate and develop real and lasting insights. Therefore, teachers of all stages, ages and subjects must be ambitious for, and expert in, developing their students’ abilities in speaking and listening, giving them time to use speech to unpack and share their thoughts with one another.

And one final gem from the Russian genius. England is one of only four countries in the Organisation for Economic Cooperation and Development in which formal schooling begins at the age of 4. Experts in early childhood have recently argued for a delay of the formal curriculum, and for the importance of play in those first years to a child’s development. Vygotsky was one of the first to identify the importance of play. He argued that it is often not pleasurable to a child because, when playing, children imagine themselves into adult roles - a teacher or a doctor, for example. To make their imaginings “real”, they set themselves rules to obey based on what they have observed of the way adults act.

Play, he argued, is an important form of self-discipline for a child. It is a fundamental foundation for formal schooling, where the ability to concentrate and defer gratification (learning is not always easy or fun) is essential. Our young children need more of it.

Indeed, I would say we need more of Vygotsky in general.

Mary Bousted is general secretary of the UK’s Association of Teachers and Lecturers.