al-Risāla al-Muʿīniyya and its Supplement - Volume 2

This second volume contains the English translations of two significant Persian astronomical treatises by Naṣīr al-Dīn al-Ṭūsī: al-Risāla al-Muʿīnyya (The Muʿīniyya treatise) and its supplement, Ḥall-i Mushkilāt-i Muʿīniyya (Resolution of the difficulties of the Muʿīniyya treatise). Both were written by Ṭūsī during his extended residence in the Ismāʿīlī fortresses of Quhistān. The translations are based on the critical edition of the Persian texts published in volume one in 2020 (here).

Following the rise of the Ilkhans and the fall of the Abbasid caliphate, Ṭūsī chose to expunge Ismāʿīlī references from some of his works, including al-Risāla al-Muʿīniyya, and Ḥall-i mushkilāt-i Muʿīniyya. Consequently, he removed all Ismāʿīlī remnants from these texts and even changed the title of the book from “al-Risāla al-Muʿīniyya” to “al-Risāla al-Mughniya” (The sufficing treatise).

These two texts are crucial for the history of astronomy, and thus their English translations make them accessible to those interested in this field. The Ḥall features Ṭūsī’s first publication of his device, now known as the Ṭūsī-couple, and its application to his planetary models.

Image of title page of Vol2 of Mu'inniya

Naṣīr al-Dīn Muḥammad al-Ṭūsī

al-Risāla al-Muʿīniyya (al-Risāla al-Mughniya) and its Supplement

Volume II: English Translation of the Persian Texts Based on the Critical Edition

Translated by: F. Jamil Ragep, Fateme Savadi, and Sajjad Nikfahm-Khubravan

ISBN 978-600-203-204-1

ISBN (Vol. 2) 978-600-203-288-1

Tehran: Written Heritage Research Institute (Miras-e Maktoob), 2024

نصیر الدین محمد طوسی

الرسالة المعینیة (الرسالة المغنیة) و حل مشکلات معینیه

جلد دوم: ترجمۀ انگلیسی

جمیل رجب، فاطمه سوادی، سجاد نیک‌فهم خوب‌روان

شابک ‫دوره: 1 – 204 – 203 – 600 – 978‬

شابک جلد دوم: 1 – 228 – 203 – 600 - 978

تهران : مؤسسه پژوهشی میراث مکتوب‏‫، 1402ش‬

PDF Online Version

Volume II: English Translation of the Persian Texts Based on the Critical Edition (complete PDF, 42MB)

Chapters of Volume 2


Title Page	(chapter PDF 200KB)
Preface	(chapter PDF 200KB)

al-Risāla al-Muʿīniyya (al-Risāla al-Mughniya)
Ismāʿīlī Preface	(chapter PDF 200KB)
Revised Preface	(chapter PDF 200KB)
Table of Contents	(chapter PDF 200KB)
BOOK I On the Introductory Propositions of this Science Which Comprises Two Chapters
CHAPTER ONE On the Introductory Propositions Pertaining to the Science of Geometry	(chapter PDF 400KB)
CHAPTER TWO On the Introductory Propositions Pertaining to the Science of Natural Philosophy	(chapter PDF 200KB)
BOOK II On the Configuration of the Upper Bodies, in Fourteen Chapters
CHAPTER ONE On the Situation of All the Simple Bodies	(chapter PDF 1200KB)
CHAPTER TWO An Exposition of the Primary and Secondary Motions, and the Names of the Great Circles	(chapter PDF 200KB)
CHAPTER THREE: An Exposition of the Circumstances of the Eighth Orb and the Fixed Stars	(chapter PDF 200KB)
CHAPTER FOUR: An Exposition of the Orbs and Motions of the Sun	(chapter PDF 200KB)
CHAPTER FIVE: An Exposition of the Orbs and Longitudinal Mo- tions of the Moon	(chapter PDF 200KB)
CHAPTER SIX: An Exposition of the Orbs and Longitudinal Motions of the Upper Planets and Venus	(chapter PDF 200KB)
CHAPTER SEVEN: An Exposition of the Orbs and Longitudinal Motions of Mercury	(chapter PDF 200KB)
CHAPTER EIGHT: On the Latitudes of the Six Planets	(chapter PDF 200KB)
CHAPTER NINE: An Exposition of the Planetary Sectors	(chapter PDF 200KB)
CHAPTER TEN: An Exposition of Retrogradation and Direct Motion, and Orientality and Occidentality	(chapter PDF 200KB)
CHAPTER ELEVEN: An Exposition of Parallax	(chapter PDF 200KB)
CHAPTER TWELVE: On the Reason for the Increase and De- crease in the Moon’s Light	(chapter PDF 200KB)
CHAPTER THIRTEEN: On the Reason for Lunar and Solar Eclipses, and the Interval Between Two Lunar or Two Solar Eclipses	(chapter PDF 200KB)
CHAPTER FOURTEEN: On Conjunctions and on Visibility and Invisibility of the Planets	(chapter PDF 200KB)
BOOK III: On the Configuration of the Earth, and the Variability of the Circumstances of Locations on It with Respect to the Changing Positions of the Upper Bodies, in Twelve Chapters
CHAPTER ONE: On the Configuration of the Earth, and a Brief Exposition of Its Circumstances	(chapter PDF 200KB)
CHAPTER TWO: On the Characteristics of Localities That Are on the Equator	(chapter PDF 200KB)
CHAPTER THREE: On the Characteristics of Localities Whose Latitude Is Less Than or Equal to the Obliquity	(chapter PDF 200KB)
CHAPTER FOUR: On the Characteristics of Localities Whose Lat- itude Is Greater Than the Obliquity, up to Where It Is Equal to the Complement of the Obliquity	(chapter PDF 200KB)
CHAPTER FIVE: On the Characteristics of Localities Whose Lat- itude Is Greater than the Complement of the Obliquity up to the Maximum Latitude	(chapter PDF 200KB)
CHAPTER SIX: On the Co-ascension of the Zodiacal Signs	(chapter PDF 200KB)
CHAPTER SEVEN: On the Equation of Daylight and the Ortive Amplitude	(chapter PDF 200KB)
CHAPTER EIGHT: On Degrees of Transit, Rising, and Setting	(chapter PDF 200KB)
CHAPTER NINE: On Determining Day and Night, Dawn and Dusk, and Hours	(chapter PDF 200KB)
CHAPTER TEN: On Year, Month, Calendar, and Intercalation	(chapter PDF 200KB)
CHAPTER ELEVEN: On Shadows and Their Circumstances	(chapter PDF 200KB)
CHAPTER TWELVE: On the Meridian Line and the Azimuth of Cities	(chapter PDF 200KB)
BOOK IV: On Determining Distances and Sizes, in Six Chapters
CHAPTER ONE: On the Measure of the Earth’s Sphere	(chapter PDF 200KB)
CHAPTER TWO: On the Ratio of the Moon’s Size to the Earth	(chapter PDF 200KB)
CHAPTER THREE: On Determining the Distances of the Moon from the Earth	(chapter PDF 200KB)
CHAPTER FOUR: On Determining the Size and Distances of the Sun	(chapter PDF 200KB)
CHAPTER FIVE: On Determining the Sizes and Distances of the Vacillating Planets	(chapter PDF 200KB)
CHAPTER SIX: On Determining the Distance and Sizes of the Fixed Stars	(chapter PDF 200KB)
Ending
Ismāʿīlī Ending	(chapter PDF 200KB)
Revised Ending	(chapter PDF 200KB)
ShortEnding	(chapter PDF 200KB)

Ḥall-i Mushkilāt-i Muʿīniyya
Ismāʿīlī Preface	(chapter PDF 200KB)
Revised Preface	(chapter PDF 200KB)
Section [One] Concerning That When the Colatitude of a Fixed Star is Greater Than the Excess of the Local Latitude over the Obliquity, It Might Become Invisible or Visible after Having Been Either Permanently Visible or Perma- nently Invisible	(chapter PDF 200KB)
Section [Two] On Why the Eccentric Orb Was Chosen for the Sun over the Epicycle	(chapter PDF 400KB)
Section [Three] Concerning the Solution of the Doubt Arising with Regard to the Motion of the Center of the Lu- nar Epicycle on the Circumference of the Deferent, and the Uniformity of that Motion about the Center of the World	(chapter PDF 200KB)
Section [Four] An Explanation of the Circuit of the Lunar Epicyclic Center and the Manner in which the Circuit of the Center of the Lunar Epicyclic Orb Comes about Due to the Motions of the Inclined and Deferent [Orbs], Which Was Referred to at the End of the Chapter on the Configuration oft he Moon	(chapter PDF 1200KB)
Section [Five] On the Configuration of the Epicycle Orbs of the Planets According to the Theory of Abū ʿAlī ibn al- Haytham	(chapter PDF 200KB)
Section [Six] On Explaining How to Determine the Station- ary Positions of the Planets on the Epicycle Orb	(chapter PDF 200KB)
Section [Seven] On Clarifying the Different Circumstances of Lunar and Solar Eclipses with Respect to Differences in Latitude,etc.	(chapter PDF 200KB)
Section [Eight] On Conceptualizing the Equation of Time	(chapter PDF 200KB)
Section [Nine] On Depicting the Indian Circle, the Azimuth of Cities, and Other Matters	(chapter PDF 200KB)
Glossary	(chapter PDF 200KB)
Index	(chapter PDF 200KB)