Besides, we must remember that Turner did not wait till his later years before beginning to paint his own impressions. He had been busy painting them ever since he had come to artistic maturity. His ‘Calais Pier’ (1803), the ‘Spithead’ (1809), ‘Petworth--Dewy Morning’ (1810), ‘Teignmouth’ and ‘Hulks on the Tamar’ (1811 and 1812), and ‘Frosty Morning’ (1813),--to name only a few--were certainly works of this kind; as were the ‘Hedging and Ditching’ of the _Liber_ and the ‘Colchester’ of the _England and Wales_ series. But there is no lack of determination in the execution of these works. The difference between Turner’s later attempts to paint his impressions and his earlier must therefore be found in his attitude towards these impressions--the principle of selection, of suppression and adjustment upon which he dealt with the data of sense-perception; and this brings us to the consideration of the _rationale_ of that vagueness of execution which we have agreed to regard as the chief characteristic of Turner’s later work. An ingenious and at first somewhat plausible attempt has been made to explain the peculiarities of Turner’s later style, on the ground that old age and failing health had brought about an actual organic change in the artist’s powers of sight. But it seems to me that Dr. Liebreich’s arguments[29] and conclusions are vitiated by his failure to discriminate between Turner’s manner of expression and the action of his eyesight. These are two clearly distinct operations. Between the act of seeing and an artist’s fully organised manner of expression, a whole host of considerations--among them the limitations and capacities of the material--interpose themselves. These considerations must all receive their due weight. I know several very short-sighted artists whose pictures are remarkable for their elaborate and sharply defined details, and there are others with strong and good eyesight, whose pictures are confused and indistinct. An artist puts into his pictures only what he chooses to put there. And when we work out in detail the reasons why Turner chose to make his drawings indistinct, we find that such considerations are quite sufficient by themselves to account for his change of style, without having recourse to any hypothetical alteration in his organs of sight.