After all, he worked in the Swiss Patent Office, so he would have known about patents and why they were advisable. So why did he choose not to patent something which he knew would be of huge significance?
Well, the reason is quite simple. If he understood patent law sufficiently well to realise the value of a patent on such an important concept as E=mc2, then he would also have understood that his idea was not patentable. Current European patent laws exclude a number of areas from patentability, one of which is scientific discoveries. We call the distinction between these unpatentable areas and the rest of technology “inherent patentability”. What this means is that most technology – anything that is outside these areas – is “inherently patentable”, i.e. inventions are patentable unless they are already known or are obvious. Ideas in the excluded fields are “inherently unpatentable”, i.e. a patent cannot be validly granted at all, regardless of whether the idea is new or unobvious.
This usually prompts people to ask how anything can be patentable – after all, at some level all inventions rely on a scientific discovery. Any electronic invention, for example, relies on the discoveries of Faraday, Volta, Ampère, Maxwell and so on. The answer lies in the rarely-mentioned proviso to the exclusion of these fields; that is, an invention is only excluded from patentability if it relates to the excluded field “as such”.
So, an invention that relates to a scientific discovery “as such” is excluded. This means that if the alleged “invention” (in fact it will then be simply an idea or concept, not an invention) is purely a scientific discovery, and nothing else, then it is excluded. If there is something more to the idea – some way in which a scientific concept is applied in the real world in order to produce a useful effect, for example, then the invention is more than a scientific discovery “as such” and is patentable.
So, discover that E=mc2, and you do not have a patentable invention.
Realise that E=mc2 means that the energy released by a fissioning atom will be huge, and could be harnessed, and that therefore radioactive elements can be used to generate power, and you have (or, had, when it was still novel) a patentable invention.
The relevant part of the European Patent Convention is Article 52, which is entitled “Patentable Inventions”, and reads:
(1) European patents shall be granted for any inventions, in all fields of technology, provided that they are new, involve an inventive step and are susceptible of industrial application.
(2) The following in particular shall not be regarded as inventions within the meaning of paragraph 1:
(a) discoveries, scientific theories and mathematical methods;
(b) aesthetic creations;
(c) schemes, rules and methods for performing mental acts, playing games or doing business, and programs for computers;
(d) presentations of information.
(3) Paragraph 2 shall exclude the patentability of the subject-matter or activities referred to therein only to the extent to which a European patent application or European patent relates to such subject-matter or activities as such.
This is also the route by which software and business methods are excluded from patentability, so the same principles apply to them. Create a cool software trick, and it will not be patentable. Use software to create a novel effect in the real world, and your invention is patentable despite the fact that it includes software.