As of July 2026, Horizon Season 4 aired in 1967 with 23 episodes — streaming now on PBS. Full episode guide and where to watch below.
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Horizon Season 4

1967 23 Episodes Documentary ⭐ 7/10

Right now you can watch Horizon Season 4 on — and it earns the access it was given. A single, tightly-focused season means there is plenty to get through without ever feeling padded. 34 viewers have already rated it on TMDB — the kind of consensus that does not happen by accident. The access the production secured is remarkable, and it does justice to it. Start it whenever you need something guaranteed to land.

Horizon Season 4 is not trying to be everything to everyone, and that focus is exactly what makes it work. What makes Horizon Season 4 work is a willingness to sit with complexity instead of resolving it neatly. Season 4 of Horizon includes 23 episodes. It aired from January 1967 to December 1967. Episodes include "Sons of Cain", "When Is a Body Dead? It was aired in 1967. Horizon Season 4 lets its subjects speak for themselves rather than shaping them into a predetermined narrative. There is real craft here, even in the moments that do not fully land.

For viewers who want their entertainment to leave them with something, Horizon Season 4 delivers on both counts. If you have run out of similar titles to watch, this is a strong next pick. Short enough to finish in a weekend, substantial enough to feel satisfying. The subject drives every choice here, not the other way around. The kind of production you finish and immediately want to read more about.

📡 Where to Watch Horizon Season 4

🇺🇸 United States
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🎬 Horizon Season 4 — Episode Guide

E1
Sons of Cain
1967-01-17
Horizon probes into whether aggressiveness is our birthright and can society live without violence?
E2
When Is a Body Dead? / How to Win Friends and Influence People
1967-01-31
Medical advances have made it possible for 'life' to be maintained in an unconscious patient who has irrevocable brain damage and who might also be dependent on artificial aids to circulation and respiration. Is it now meaningless to define 'death' as the cessation of a heart beat? Why do so many p...
E3
How Best to Make a Man / How Best to Make a Scientist
1967-02-14
In this episode, Horizon looks at a new school of mathematics and physics near Novosibirsk in Siberia, Russia. This school uses a competition held for Russian school children to qualify new students.
E4
Dynamo - The Life of Michael Faraday
1967-02-28
Horizon profiles the life of the greatest physical scientist: Michael Faraday. Crucial events of his scientific career in science are reconstructed.
E5
Migraine
1967-03-14
Horizon looks at some research recently carried out into the migraine headache and the means to provide treatment for it.
E6
How Safe Is Surgery?
1967-03-28
Horizon probes in the danger of germs and infection in the operating theater and the methods currently used to prevent contamination.
E7
Sleep and Dreams
1967-04-11
Joel, a healthy young American, is reduced to a restless neurotic state after being deprived of his dreams for three nights. Mr Bates, an eighty-four-year-old ex-milk man, has never dreamed in his life, or so he says until he is woken by scientists in the middle of a dream trip to New York.
E8
The Shape of War to Come
1967-04-25
Will the next major war be fought with biological and chemical weapons? What are the available weapons? What is the horror they can cause? Is there any moral justification for their use?
E9
Memory
1967-05-09
Horizon explores the part of the human brain devoted to memory.
E10
Masters of the Desert
1967-05-23
Horizon reports on the methods being used to irrigate the Negev Desert, making it fertile based on the methods of ancient civilizations.
E11
Cancer - The Search for the Virus
1967-06-06
In this the first of two programmes dealing with cancer, Horizon looks at the intensive search now going on to discover whether a virus is one of the causes of cancer in humans and at the implications of this search in the treatment for such killer diseases as leukemia.
E12
Cancer - The Smoker's Gamble
1967-06-20
Why is there doubt in so many people's minds about the relationship between lung cancer and smoking? Tonight's programme examines the latest scientific evidence in detail.
E13
Science and the Supernatural
1967-07-04
Horizon explores the work in the developmental field of Extra Sensory Perception (ESP).
E14
Hypnosis
1967-07-18
Horizon explores the misconceptions that people have about what hypnosis is and looks at the medical implications of what it can do.
E15
The War of the Boffins
1967-09-12
During the human struggles between the British and German air forces ... another conflict was going on step by step, month by month. This was a secret war whose battles were lost or won unknown to the public: and only with difficulty is it comprehended even now by those outside the smalt high scient...
E17
Aspects of Alcohol
1967-09-26
Horizon looks at a Scottish chemist's unusual application for whisky: a measure of radioactive carbon 14 used for determining how old an object is.
E18
Lords of the Sea
1967-10-10
Horizon looks into how man is learning to survive in the oceans.
E19
Will Art Last?
1967-10-24
In this episode, Horizon reports on new materials that are being used as art media by gaining inspiration from factory and industrial processes.
E20
Air Safety: The Unknown Factor
1967-11-17
Horizon investigates air navigation and flight safety.
E21
The Life and Death of the Pine Processionary
1967-11-21
Horizon reports on the problem of exterminating the pine processionary caterpillars infestation from the pine forests of Provence, Canada.

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