52 LESSONS FROM NATURE. [CHAP. II. 



by the acts of our own minds; though it has been impossible 

 (owing, at least in part, to the force of nature and natural 

 reason) not to use language implying- the acceptance of the 

 ordinary beliefs respecting the existence of a real objective 

 world external to our own minds. 



The facts referred to in these first two chapters may be 

 summary summed up as follows : 



S5&amp;gt;nT The consideration of our own continued existence 



reveals to us objective truth and our possession of it. 



Our self-consciousness also reveals to us that, similarly, 

 there are universal, necessary, undemonstrable truths (as, e.g., 

 &quot; What thinks exists &quot;), and that we can know them. 



Similarly, our intellect shows us the validity of our own 

 reason, and the objective validity of the syllogism which 

 renders implicit truth explicit to us. We see that the 

 ultimate criterion of truth is a mental state of conviction 

 produced by our clearly perceiving that a given proposition 

 is positively true necessarily, and r.ot that we are in a state of 

 mere impotence not to think it. Such a test constitutes the 

 principle of certitude. This principle, those of identity and 

 contradiction, together with the validity of the reasoning 

 process and our intuition of enduring self-existence, are five 

 elements which together constitute a firm foundation upon 

 which may be raised the logical edifice of coherent truths. 

 All these truths have our self-consciousness, our knowledge 

 of the enduring Ego, as their starting-point, and are involved 

 in that knowledge and flow from it. 



Other consequences also necessarily follow from the truths 

 here maintained. If our certainty as to our own con 

 tinuous past existence is valid (and we have seen at what a 

 price it can alone be denied), we may be equally certain 

 that, if there are other beings like ourselves who can know 

 us, the present existence of each of us is an objective truth 

 to such other beings, and our intellect carries us at once also 

 in this way from subjectivity to objectivity ; to the world of 

 existences outside our consciousness from the world of our 

 conscious being. 



