The Online Library of Liberty

A project of Liberty Fund, Inc.

• On the Improvement of the Understanding.
• The Ethics.
• Part I.: Concerning God.
• Part II.: Of the Nature and Origin of the Mind.
• Part III.: On the Origin and Nature of the Emotions.
• Part IV.: Of Human Bondage, Or the Strength of the Emotions.
• Part V.: Of the Power of the Understanding, Or of Human Freedom.
• Spinoza’s Correspondence.
• Letter I. (i. 1 ): Henry Oldenburg 2 to B. De Spinoza.
• Letter II. (ii.): Spinoza to Oldenburg.
• Letter III. (iii.): Oldenburg to Spinoza.
• Letter IV. (iv.): Spinoza to Oldenburg.
• Letter V. (v.): Oldenburg to Spinoza.
• Letter VI. (vi.): Spinoza to Oldenburg.
• Letter VII. (vii.): Oldenburg to Spinoza.
• Letter Viii (xi.): Oldenburg to Spinoza.
• Letter IX. (xiii.): Spinoza to Oldenburg.
• Letters X.—XIV. 1: Letter XIII. A.: Oldenburg to Spinoza.
• Letter XV. (xxxii.): Spinoza to Oldenburg.
• Letter XVI. (xxxiii.): Oldenburg to Spinoza.
• Letter XVII. (lxi.): Oldenburg to Spinoza.
• Letter XVIII. (lxii.): Oldenburg to Spinoza.
• Letter XIX. (lxviii.): Spinoza to Oldenburg.
• Letter XX. (lxxi.): Oldenburg to Spinoza.
• Letter XXI. (lxxiii.): Spinoza to Oldenburg.
• Letter XXII. (lxxiv.): Oldenburg to Spinoza.
• Letter XXIII. (lxxv.): Spinoza to Oldenburg.
• Letter XXIV. (lxxvii.): Oldenburg to Spinoza.
• Letter XXV. (lxxviii.)
• Letter XXV. A.: Oldenburg to Spinoza.
• Letter XXVI. (viii.): Simon De Vries 1 to Spinoza.
• Letter XXVII. (ix.): Spinoza to Simon De Vries.
• Letter XXVIII. (x.): Spinoza to Simon De Vries.
• Letter XXIX. (xii.): Spinoza to L. M. 1 (lewis Meyer).
• Letter XXIX. A. 1: Spinoza to Lewis Meyer.
• Letter XXX. (xvii.): Spinoza to Peter Balling. 1
• Letter XXXI. (xviii.): William De Blyenbergh 1 to Spinoza.
• Letter XXXII. (xix.): Spinoza to Blyenbergh.
• Letter XXXIII. (xx.): Blyenbergh to Spinoza.
• Letter XXXIV. (xxi.): Spinoza to Blyenbergh.
• Letter XXXV. (xxii.): Blyenbergh to Spinoza.
• Letter XXXVI. (xxiii.): Spinoza to Blyenbergh.
• Letter XXXVII. (xxiv.): Blyenbergh to Spinoza.
• Letter XXXVIII. (xxvii.): Spinoza to Blyenbergh.
• Letter XXXIX.: Spinoza to Christian Huyghens.
• Letter Xl. (xxxv.): Spinoza to Christian Huyghens.
• Letter Xli. (xxxvi.): Spinoza to Christian Huyghens.
• Letter Xli. A.: Spinoza to * * * * * 1 (may Or June, 1665).
• Letter Xlii. (xxxvii.): Spinoza to I. B. 1
• Letter Xliii. (xxxviii.): Spinoza to I. V. M. 1
• Letters Xliv., Xlv., Xlvi. (xxxix., Xl., Xli.): Spinoza to I. I. 2
• Xliv.
• Xlv.
• Xlvi.
• Letter Xlvii. (xliv.): Spinoza to I. I.
• Letter Xlviii.
• Letter Xlix.: Spinoza to Isaac Orobio. 1
• Letter L. (l.): Spinoza to Jarig Jellis.
• Letter Li. (xlv.): Godfrey Leibnitz to Spinoza.
• Letter Lii. (xlvi.): Spinoza to Leibnitz.
• Letter Liii. (xlvii.): Fabritius to Spinoza.
• Letter Liv. (xlviii.): Spinoza to Fabritius.
• Letter Lv. (li.): Hugo Boxel to Spinoza.
• Letter Lvi. (lii.): Spinoza to Hugo Boxel.
• Letter Lvii. (liii.): Hugo Boxel to Spinoza.
• Letter Lviii. (liv.): Spinoza to Hugo Boxel.
• Letter Lix. (lv.): Hugo Boxel to Spinoza.
• Letter Lx. (lvi.): Spinoza to Hugo Boxel.
• Letter Lxi. (lvii.): * * * * * to Spinoza. 1
• Letter Lxii. (lviii.): Spinoza to * * * * * 2 (the Hague, October, 1674).
• Letter Lxiii. (lix.): * * * * * to Spinoza. 1
• Letter Lxiv. (lx.): Spinoza to * * * * *. 1
• Letter Lxv. (lxiii.): G. H. Schaller to Spinoza. 1
• Letter Lxvi. (lxiv.): Spinoza to * * * * *. 1
• Letter Lxvii. (lxv.): * * * * * 1 to Spinoza.
• Letter Lxviii. (lxvi.): Spinoza to * * * * *. 1
• Letter Lxviii. A.: G. H. Schaller to Spinoza.
• Letter Lxviii. B.: Spinoza to Schaller.
• Letter Lxix. (lxxx.): * * * * * 1 to Spinoza.
• Letter Lxx. (lxxxi.): Spinoza to * * * * * 1
• Letter Lxxi. (lxxxii.): * * * * * 1 to Spinoza.
• Letter Lxxii. (lxxxiii.): Spinoza to * * * * 1
• Letter Lxxiii. (lxvii.): Albert Burgh to Spinoza.
• Letter Lxxiv. (lxxvi.): Spinoza to Albert Burgh.
• Letter Lxxv. (lxix.): Spinoza to Lambert Van Velthuysen ( Doctor of Medicine At Utrecht. ) 1

LETTER XXVIII. (X.)

Spinoza to Simon de Vries.

Respected Friend,—

You ask me if we have need of experience, in order to know whether the definition of a given attribute is true. To this I answer, that we never need experience, except in cases when the existence of the thing cannot be inferred from its definition, as, for instance, the existence of modes (which cannot be inferred from their definition); experience is not needed, when the existence of the things in question is not distinguished from their essence, and is therefore inferred from their definition. This can never be taught us by any experience, for experience does not teach us any essences of things; the utmost it can do is to set our mind thinking about definite essences only. Wherefore, when the existence of attributes does not differ from their essence, no experience is capable of attaining it for us.

To your further question, whether things and their modifications are eternal truths, I answer: Certainly. If you ask me, why I do not call them eternal truths, I answer, in order to distinguish them, in accordance with general usage, from those propositions, which do not make manifest any particular thing or modification of a thing; for example, nothing comes from nothing. These and such like propositions are, I repeat, called eternal truths simply, the meaning merely being, that they have no standpoint external to the mind, &c.