Of this,at first view,every man,in his own forum,ought to judge without appeal.But,strange as it may appear,we are often at a loss to know what ideas we have of things,or whether we have any ideas at all upon some subjects.It even requires a good deal of attention to be thoroughly satisfied on this head.Since I wrote these papers,I found two very striking instances of the possibility there is that a man may hear words without having any idea of the things which they represent,and yet afterwards be capable of returning them to others,combined in a new way,and with great propriety,energy and instruction.The first instance is that of Mr.Blacklock,a poet blind from his birth.Few men blessed with the most perfect sight can describe visual objects with more spirit and justness than this blind man;which cannot possibly be attributed to his having a clearer conception of the things he describes than is common to other persons.Mr.Spence,in an elegant preface which he has written to the works of this poet,reasons very ingeniously,and,I imagine,for the most part,very rightly,upon the cause of this extraordinary phenomenon;but I cannot altogether agree with him,that some improprieties in language and thought,which occur in these poems,have arisen from the blind poet's imperfect conception of visual objects,since such improprieties,and much greater,may be found in writers even of a higher class than Mr.Blacklock,and who notwithstanding possessed the faculty of seeing in its full perfection.
Here is a poet doubtless as much affected by his own deions as any that reads them can be;and yet he is affected with this strong enthusiasm by things of which he neither has nor can possibly have any idea further than that of a bare sound:and why may not those who read his works be affected in the same manner that he was,with as little of any real ideas of the things described?The second instance is of Mr.Saunderson,professor of mathematics in the university of Cambridge.This learned man had acquired great knowledge in natural philosophy,in astronomy,and whatever sciences depend upon mathematical skill.What was the most extraordinary and the most to my purpose,he gave excellent lectures upon light and colours;and this man taught others the theory of these ideas which they had,and which he himself undoubtedly had not.But it is probable that the words red,blue,green,answered to him as well as the ideas of the colours themselves;
for the ideas of greater or lesser degrees of refrangibility being applied to these words,and the blind man being instructed in what other respects they were found to agree or to disagree,it was as easy for him to reason upon the words,as if he had been fully master of the ideas.Indeed it must be owned he could make no new discoveries in the way of experiment.He did nothing but what we do every day in common discourse.When I wrote this last sentence,and used the words every day and common discourse,I had no images in my mind of any succession of time;nor of men in conference with each other;nor do I imagine that the reader will have any such ideas on reading it.
Neither when I spoke of red,or blue,and green,as well as refrangibility,had I these several colours or the rays of light passing into a different medium,and there diverted from their course,painted before me in the way of images.
I know very well that the mind possesses a faculty of raising such images at pleasure;but then an act of the will is necessary to this;and in ordinary conversation or reading it is very rarely that any image at all is excited in the mind.
If I say,"I shall go to Italy next summer,"I am well understood.Yet I believe nobody has by this painted in his imagination the exact figure of the speaker passing by land or by water,or both;sometimes on horseback,sometimes in a carriage;with all the particulars of the journey.Still less has he any idea of Italy,the country to which I propose to go;or of the greenness of the fields,the ripening of the fruits,and the warmth of the air,with the change to this from a different season,which are the ideas for which the word summer is substituted:but least of all has he any image from the word next;
for this word stands for the idea of many summers,with the exclusion of all but one:and surely the man who says next summer,has no images of such a succession and such an exclusion.
In short,it is not only of those ideas which are commonly called abstract,and of which no image at all can be formed,but even of particular,real beings,that we converse without any idea of them excited in the imagination;as will certainly appear on a diligent examination of our minds.Indeed,so little does poetry depend for its effect on the power of raising sensible images,that I am convinced it would lose a very considerable part of its energy,if this were the necessary result of all deion.Because that union of affecting words,which is the most powerful of all poetical instruments,would frequently lose its force,along with its propriety and consistency,if the sensible images were always excited.There is not perhaps in the whole Eneid a more grand and laboured passage than the deion of Vulcan's cavern in Etna,and the works that are there carried on.Virgil dwells particularly on the formation of the thunder,which he describes unfinished under the hammers of the Cyclops.
But what are the principles of this extraordinary composition?
Tres imbris torti radios,tres nubis aquosae Addiderant;rutili tres ignis,et alitis austri:Fulgores nunc terrificos,sonitumque,metumque Miscebant operi,flammisque sequacibus iras.
