Volkelius John , (Germ. Volkel,) of the town of Grimma, in the Circle of Meissen, was known, among the Crypto-Socinians of Altorf, by the name of Popilius, or Populceus, which is a Latinized form of the German name Volkel. Of his history before he came into Poland, and joined the Socinians, no particulars are recorded ; but Zeltner, more than a century ago, observed, that it would be worth the while of those, who were acquainted with the division of Saxony in which he was born, to institute an inquiry into the circumstances, which led him to connect himself with the Socinian party. As yet nothing has been ascertained respecting his early history, beyond the mere fact, that he was one of the beneficiaries of the Elector of Saxony, and studied Theology at Wittenberg in 1578, into the Augustan College of which place he was received as an exhibitioner, on the twenty-first of September in that year. On account of his connexion with that seat of learning, he is sometimes called, in the Synodical Acts of the Socinians, "Magister Wittebergensis;" and Schomann, in his Will, designates him "Magister noster." But whether he was admitted to his Master's degree in the University of Wittenberg is uncertain.

Of his mental endowments, and his unwearied efforts to promote the interests of the Socinian Church, the six letters addressed to him by Faust Socin, in his printed correspondence, afford sufficient evidence. For some time, indeed, he was the amanuensis of Socin, and regularly employed in writing from his dictation. By constant and familiar practice in this way, he became thoroughly acquainted with the mind of that great man, whose opinions he made his own, and embodied in his work "On true Religion," which may be regarded as a compendium of the writings of Socin.  

In the year 1585, at the Synod of Chmielnik, as we read in the Manuscript Acts, Volkelius was admitted a full member of the Socinian Church, by re-baptism. By the authority of the same Synod, he was appointed Master of the School at Wengrow in the same year. For some time he performed the duties of this office, in conjunction with the charge of a congregation. We learn both from the Synodical Acts, and a letter written to him by Faust Socin in 1594, that he was first appointed Minister of the Church in Philipovia, in the Grand Duchy of Lithuania. Subsequently, in the year 1610, he removed to the Church of Reiovice ; and in 1611, or 1612, to Smigel. But although his hearers at Smigel had the highest respect for him, which they testified at the Synod of Racow in 1612, yet in the month of May, 1613, he was excluded from the ministerial office, by a decree of Synod, for contumacy and insubordination ; and suspended, till he should give undoubted proofs of his submission to the authority of the Synod. What his offence had been is not recorded ; but in May, 1614, he was re-admitted to the discharge of his ministerial functions at the Synod of Racow, after having made a declaration of his submission and obedience.

 He died at Smigel in 1618 ; and in the year following, at a Synod held on the 5th of May, the Church of that place requested, that a successor might be appointed.

The Synodical Acts afford evidence that Volkelius was married ; for the members of his congregation at Smigel, in 1612, requested permission of the Synod of Racow, to bring his wife to Smigel. But she seems to have died before him, because no mention is made of any grant to his widow ; and such grants to Ministers' widows were always particularly specified in the accounts of the Synod. He left a daughter, Catharine, to whom, at a Synod in 1621, two hundred and seventy-eight florins were granted as a dowry. 

Volkelius was distinguished for his acuteness and eloquence. In his writings he is neat and elegant, and in almost all respects a follower of Faust Socin. He left behind him in manuscript some Common-places and Discourses, as well as his great work "On true Religion;" and he assisted, though slightly, in completing the Racovian Catechism, and illustrated it with notes. His published works are as follow.
  

1. The Guardian Knot of Martin Smiglecius untied by John Volkelius. Racow, Typ. Seb. Sternacki, 1613, 8vo. This work is one of extreme rarity. In that to which it was a reply, and which was entitled "The Gordian Knot," Martin Smiglecius, the Jesuit, endeavoured to shew, that there could be no truly ordained, and properly qualified Christian Minister, out of the pale of the Romish Church. To the arguments adduced by him with that view, Volkelius replied, as far as the Socinians were concerned ; leaving it to other Churches to make what reply they thought proper. Smiglecius answered Volkelius in 1614 ; and in 1618, Volkelius published 

2. An Answer to the unsatisfactory "Refutation" of "The Guardian Knot of Martin Smiglecius untied," by John Volkelius. Racow, 1618, 4to. In this controversy Valentine Smalcius took the part of his friend Volkelius, in some Notes on Smiglecius's pretended "Refutation," which were published at Racow in 1614. On the part of the Calvinists, answers to Smiglecius were written by James Zaborowski, and Andrew Firley.

3. Five Books of John Volkelius, of Meissen, on true Religion ; to which is prefixed a Book of John Crellius, Frank, on God and his Attributes ; so as to form one Work. Racow, Typ. Seb. Sternacki, 1630, 4to. The Books of Volkelius were printed, either wholly or in part, before Crellius had finished the composition of his. Ruarus, in a letter to Francis Limborch, written in 1620, alludes to Volkelius's portion of this work as already before the public ; but says of it, "capite adhuc caret, quod Crellius noster adornat." It was not till ten years later that the First Book made its appearance. Hence the order of the pages is twofold. The First Book, which was supplied by Crellius, fills about one-third part of the Volume, and extends as far as page 352. The remaining five Books, which were written by Volkelius, occupy 715 pages. The subject of the First Book is indicated in the title-page.

The Second is On the Works of God ; the Third, On the Christian Religion ; the Fourth, On the Precepts of Christ ; the Fifth, On the Aids requisite for Perseverance in Faith and Piety ; and the Sixth, On the Church of Christ. The Preface is written by Crellius ; and there are copious Indexes of passages of Scripture explained and illustrated, and of the principal matters treated upon in the course of the volume. The work ranks among the principal systems of the Socinian doctrine, and was regarded by the Socinians themselves as occupying the next place to the Racovian Catechism. Grotius, in a letter addressed to John Crellius, (Epp. Praestant. et Erudit. Virorum, p. 763,) speaks of it in the following terms. "I find many observations in it, made with the greatest judgment ; but on this I congratulate the age, that men are found, who do not attach so much importance to subtle controversies, as to the true improvement of life, and daily advancement towards holiness. In the opinion of Reimannus there is in Volkelius much genius, no slight degree of acumen, and the greatest diligence. What lies scattered up and down in the writings of Socin and his followers, we have here before us collected into a single volume." Volkelius's portion of this admirable work was composed as early as the year 1612 ; and he was repeatedly urged to revise it, which he did after much importunity, so as to prepare it for the press in 1617. But its publication was delayed by his death, which took place in the year following. In 1619, Daniel Franconius was commissioned to write out a fair copy, and transmit it without delay to Racow, in order that it might be committed to the press, after having undergone the usual previous revision. The copy was soon made; and in 1622 a resolution was passed, that it should be handed over for revision and correction to Moscorovius, Goslavius, Smalcius, Crellius and Ruarus, with a view to its publication. At the next Synod, in 1623, 110 florins were voted for this purpose; in addition to which the Messrs. Czaplic promised two or three hundred, and Stanislaus Lubieniecius contributed two hundred and thirty more. In 1624, Crellius was again urged to use all speed in the work of revision ; and in 1625, he was requested to suspend all his other labours, in order to complete this, and particularly to re-compose the first Book, which, as it would seem, underwent a thorough change, so as to appear at length as an original composition of Crellius. In 1629, the work was sent to the press ; and in addition to the sums already mentioned, Cikovius contributed a hundred florins, and John Krokier another hundred, towards the expenses of publication. All this shews, of how great importance the Socinians thought this work of Volkelius ; and what extraordinary care was taken, in preparing it for the public eye. It appears, from the title-page, that the first edition issued from the press in 1630 ; and so much was it sought after, that Sandius records an instance of a copy having been sold, in France, for the sum of twentyfive Hungarian pistoles. A second edition was clandestinely printed at Amsterdam, in 1642, 4to., by the firm of Blaeu, where, according to some accounts, five hundred copies, according to others, four hundred and fifty, were publicly burnt, by order of the Magistrates, on the 20th of January, 1642. A fine of twelve hundred florins was at the same time imposed upon the printers: but this fine was afterwards remitted. Curcellaeus, in writing to his friend Ruarus, Feb. 8th, 1642, says that the reason of this edition being committed to the flames was, that Volkelius referred the doctrine of the Trinity to Satan as its author. In another letter, written to the same friend on the 12th of April in the same year, he says, that the new Magistrates, elected according to custom at the beginning of February, had rescinded the sentence passed by their predecessors upon the printers, who, however, had been so alarmed by what had taken place, that they were not likely, in future, to engage in printing works of that description. Vogt, who possessed a copy of the second edition, says, that it had in the title-page no indication of time, or place, or printer's name. A Dutch translation of it was published at Rotterdam in 1649, 4to., in the title-page of which it was stated, that the work had been previously condemned and burnt. The title-page also set forth, that this version was published by a Lover of the Kingdom of Christ, for the Instruction and Confirmation of the Subjects of Christ in Holland. Maresius, in his " Hydra Socinianismi expugnata," published at Groningen, in three Volumes, 4to., 1651—1662, inserted the whole of Volkelius's work, with a weak and frigid reply of his own. It has been thought, that this was done by the advice of his bookseller, to aid the sale of his own refutation. 

4. Erklarung der Meinungen von dem alleinigen Gotte. 1646, 4to. 

(Vidend. Sandii B. A. p. 96. Bayle, Diet. Hist, et Crit. Art. VolKelius. Bock, Hist. Ant. T. I. pp. 992—1003. Zettneri Hist. CryptoSocinismi Altorf. pp. 360—362. Schomanni Testamentum, p. 196, Anno 1585. Ruari Epistolae, Cent. i. N. 86, 87. Thomte Crenii Anim. Philol. et Hist. P. v. p. 264. Bibl. Fratr. Polon. T. I . pp. 451—455. Vogt, Catal. Libr. Barior. p. 714.)