Biography.guide
Home › People › Physician › Thomas Laycock
Portrait of Thomas Laycock

Thomas Laycock

1812 – 1876

British neurophysiologist

Physician Neurophysiologist
Don't just read it — keep itBiographies to ownE-book · Audio · Video From $7 →

About Thomas Laycock

Lived 1812 – 1876 (aged 63–64). Thomas Laycock was a British physician and neurophysiologist.

Thomas Laycock FRSE FRCPE (10 August 1812 – 21 September 1876) was an English physician and neurophysiologist who was a native of Bedale near York. Among medical historians, he is best known for his influence on John Hughlings Jackson and the psychiatrist James Crichton-Browne. Laycock's interests were the nervous system and psychology; he is known as one of the founders of physiological psychology. He was the first to formulate the concept of reflex action within the brain, and is also known for his classification of mental illnesses.

Early life and education Laycock was born on 10 August 1812 in Wetherby, Yorkshire, and was the son of Wesleyan minister Rev Thomas Laycock. His mother was the daughter of a Cheshire squire.

He attended the Wesleyan Academy on Woodhouse Grove in West Yorkshire from 1821–1827. Here he was a contemporary of John William Draper. At the age of fifteen, Laycock trained as an apprentice surgeon-apothecary under William Spence and John Spence in Bedale. While in Paris, Laycock studied anatomy and physiology under Jacques Lisfranc de St. Martin and Velpeau at la Pitié.

In 1852, Laycock first encountered Hughlings Jackson, a new student; he also taught Jonathan Hutchinson whom Jackson was to meet in 1859 and share a house with at 14 Finsbury Circus, London for three years.

In 1855, the position of chair of medicine at the University of Edinburgh became open. The position was highly desired and candidates would canvas for the spot.

Laycock set up a course for medical psychology and mental diseases as a professor of medicine at Edinburgh.

He is buried a short distance from his home, in one of the upper terraces of St Johns Episcopal Church at the west end of Princes Street.

Teachings

Reflex function of the brain Following the work of Robert Whytt and Marshall Hall, Laycock studied the reflex arc in relation to the nervous system. While Hall believed that the reflex arc was mediated by the spinal cord, separate from the cerebrum, Laycock argued that the brain underwent the same reflex patterns as the rest of the nervous system. After learning the German language, he translated books by Johann August Unzer, who studied afferent and efferent reflexes. Unzer centralised the nervous system in the spinal cord, such that reflexes could occur even without a functional brain, which only controls conscious activity. Laycock disagreed with Unzer's centralisation in the spinal root ganglia; Laycock stated: "The brain, although the organ of consciousness, was subject to the laws of reflex action and in this respect it did not differ from other ganglia of the nervous system."

Nature and methodology Laycock was a teleologist. He also held a fundamental belief in the "unity of nature", and saw nature as working through an unconsciously acting principle of organisation. Through his teleological approach, he argued that the origins of the nervous system were based on a natural force which he named the "Unconsciously Acting Principle for Intelligence." This force provided a plan for organism construction, regulated organisms based on survival instinct, and acted on the brain to provoke the phenomena of thought. Laycock saw nature as purposeful in creating this force, which ultimately results in a self-conscious mind, and an unconscious intelligence where reflexes were seeded. Because of his teleological approach to seeing nature through a lens of purpose, Laycock used observation as his principal method of scientific inquiry. He did not advocate for microscopic experimentation, which he saw as unnecessary in studying nature's biological forces. Rather, he preferred passive observation of purposeful phenomena in nature, from which theories could be inducted.

Classification of psychiatric disorders In 1863, Laycock published a paper on the classification of psychiatric disorders. On the classification, he said: "If we further analyse the standard as applied to the naming and classification of mental diseases in general, we find it includes attributes or qualities in common with others of the same age, sex, or social position". Laycock recognised that many factors were included in classification, and therefore absolute standards were not feasible.

Laycock was also aware of the different possible approaches in classification, but he used a biological and neurological approach to classification. He classified insanity into three types: orectic insanity, thymic insanity, and phrenic insanity. Each type of insanity was associated with a disorder in encephalic centers that controlled instincts, feelings, or reason.

The biological approach to classifying mental disorders was due to Laycock's belief that the mind was a result of the brain. On insanity, his definition was: "a chronic disorder of the brain by which the mental condition of the individual is so modified that he is deprived wholly or in part of common sense." He explained moral insanity and mania through the concept of "reversed evolution," a concept that was later furthered by John Hughlings Jackson.

Laycock became president of the Medico Psychological Association in 1869. He thought that people who were mentally handicapped could also be mentally ill, which was not yet a generally accepted idea during his time.

Legacy Historians have a hard time crediting Laycock for his findings in the existence of the cerebral reflex and the continuity of the nervous system throughout the animal species because of his non-scientific methodology. Laycock's writing style was also very dense, and difficult to understand due to the lack of brevity. In his writings, he would include many philosophical ideas and expressions, which would hinder the understanding of his concepts.

Laycock's ideas reached modern day acceptance through his student John Hughlings Jackson, who recast the concept of the continuity of nervous systems in animals through evolutionary proof. Jackson's scientific approach gained much more acceptance than Laycock's philosophical, observational approach. Laycock generalised the reflex patterns of the entire nervous system and the synthesis of nervous function. Ivan Pavlov, Charles Scott Sherrington, and Sigmund Freud later expanded upon Laycock's philosophical observations of nervous function synthesis.

The honors received by Laycock include: fellowship in the Royal Society, Edinburgh, fellowship in the Royal College of Physicians of Edinburgh, and Physician in Ordinary to the Queen of Scotland.

Publications

Religio Medicorum: a Critical Essay on Medical Ethics (1848) The Social and Political Relations of Drunkenness (1857) Mind and Brain (1860)

Biography shop

Don’t just read it —
keep it.

Full-length biographies made to live with: read them, listen on the way to work, watch them tonight.

  • E-book
  • Audio
  • Video
Browse the shop — from $7

Instant download · yours to keep · every purchase keeps this site free

Important facts

Born
1812
Birth century
Died
1876
Education
University College London
Employers
University of Edinburgh

People in Thomas Laycock's life

Named in this biography and alive at the same time

Contemporaries

People whose lives overlapped Thomas Laycock's

Frequently asked questions

Who was Thomas Laycock?

British neurophysiologist (1812–1876)

When was Thomas Laycock born?

Thomas Laycock was born in 1812.

When did Thomas Laycock die?

Thomas Laycock died in 1876.

What was Thomas Laycock's occupation?

Thomas Laycock was a physician and neurophysiologist.

What nationality was Thomas Laycock?

Thomas Laycock was British.

Sources & further reading

· Wikipedia: Thomas Laycock

· Wikidata: Q7791753

· DBpedia: Thomas Laycock (physiologist)

Cite this page

APA: Biography.guide. (2026). Thomas Laycock. https://biography.guide/thomas-laycock/

MLA: "Thomas Laycock." Biography.guide, https://biography.guide/thomas-laycock/.

Chicago: "Thomas Laycock." Biography.guide. https://biography.guide/thomas-laycock/.

Data last updated: 2026-09-27 · Spot an error? Report a correction.

Page generated 2026-09-27 05:17 UTC