Subject: The Synthesis of Algorithmic Systems
From: "Alan J. Perlis" <[email-masked]>
To: Alan Turing <[email-masked]>
Date: Sat, 01 Jan 1966 12:00:00 -0400

Both knowledge and wisdom extend man's reach. Knowledge led to computers, 
wisdom to chopsticks. Unfortunately our association is overinvolved with 
the former. The latter will have to wait for a more sublime day. 
On what does and will the fame of Turing rest? That he proved a theorem 
showing that for a general computing device--later dubbed a "Turing 
machine"--there existed functions which it could not compute? I doubt it. 
More likely it rests on the model he invented and employed: his formal 
mechanism. 
This model has captured the imagination and mobilized the thoughts of a 
generation of scientists. It has provided a basis for arguments leading to 
theories. His model has proved so useful that its generated activity has 
been distributed not only in mathematics, but through several technologies 
as well. The arguments that have been employed are not always formal and 
the consequent creations not all abstract. 
Indeed a most fruitful consequence of the Turing machine has been with the 
creation, study and computation of functions which are computable, i.e., in 
computer programming. This is not surprising since computers can compute so 
much more than we yet know how to specify. 
I am sure that all will agree that this model has been enormously valuable. 
History will forgive me for not devoting any attention in this lecture to 
the effect which Turing had on the development of the general-purpose 
digital computer, which has further accelerated our involvement with the 
theory and practice of computation. 
Since the appearance of Turing's model there have, of course, been others 
which have concerned and benefited us in computing. I think, however, that 
only one has had an effect as great as Turing's: the formal mechanism 
called ALGOL Many will immediately disagree, pointing out that too few of 
us have understood it or used it. 
While such has, unhappily, been the case, it is not the point. The impulse 
given by ALGOL to the development of research in computer science is 
relevant while the number of adherents is not. ALGOL, too, has mobilized 
our thoughts and has provided us with a basis for our arguments.