PHYSIOLOGY. 143 



" 2. I go on to consider the error of thought, judgment, or 

 will, which is properly placed under the title of delirium. It 

 may perhaps be considered as unnecessary to say what this state 

 is, as no one can be supposed to know it except those who are or 

 have been in the state themselves; still it may be useful to consider 

 wherein it consists. Gaubius has done so ; he observes that delirium 

 appears in three different shapes ( 732.) : 'Delirare dicitur, (1,) 

 qui cum vigilat, somnianti tamen similis, ideas, sibi ab internis 

 causis natas, ad res externas refert, percipitque adeo ac existimat 

 praesentia esse,quae absunt; turn, (2,) qui ideas undecunque ortas 

 praepostere componit, disjungit, judicium ferens a com muni 

 sensu aberrans ; et (3,) qui prater rationem, vi morbi, alienos 

 a suis mores induit, motibusque animi abstrahitur insolitis, ef- 

 frenatioribus.' You will readily perceive that the foregoing 

 passage amounts to this : that the three states of delirium are 

 false imagination, erroneous judgment, and irregular passion. 

 The three operations of thought are perception, judgment, and 

 will : and delirium is distinguished as it lies in one or other of 

 these. 



" The first state I have called false imagination, in compliance 

 to common language ; but in LXIX. I have said that we 

 strictly call imagination the state in which the sensations, which 

 usually arise from external objects, take place without the pre- 

 sence of these ; and it is this that constitutes Gaubius's first 

 kind of delirium. I hinted at the causes of this as far as we can 

 prosecute them, (p. 50.), and I considered them as always in- 

 ternal impressions ; but I mentioned my doubts whether some 

 of the hallucinations may not sometimes depend upon the nerves 

 of the organ itself. 



" The second kind of delirium, error in judgment, is not quite 

 so easily explained : you may observe, that thought depends upon 

 memory, upon the power which we have of recalling the ideas of a 

 great number of things which are not present ; but memory de- 

 pends upon an association of ideas, and it easily runs over that 

 train of associations that it has been accustomed to. Thus, I come 

 to a gentleman and tell him that he owes me five guineas ; he hesi- 

 tates, perhaps unwilling or willing to remember, and asks how do I 

 owe you such a sum ? I mention the persons that were present 

 perhaps, the reason why he wanted it, &c. ; and, if he is an 



