Talking About The Dark Age

Due to Russell, the dark age of Western Europe is from 6th century A.D. to 10th century A.D. And in a larger view, the so-called Middle Ages are from the falling of the Western Empire until the Renaissance, which last about 1000 years.

During this era, Western Europe suffered from the barbarian invasions from the west and the north, and even the rise of Islam from the south and the east. Civilization was diminished. The Rome law was inherited partly by the papal party, but it banished non-orthodox philosophers, and forbid the teaching of secular knowledge. The persecution on heresies resulted in the spiritual separation among different parts of the former Rome Empire, which benefited the Mohammedans to conquer the small Asian, North Africa, and even Spain.

This is the overview of the dark age. However, there are still many things that I misunderstood before. First, for the rising of the papal power, I used to blame it to the avarice of the popes, whose ambition was to become the new Emperor of the Western Empire. However, due to Russell's talk about that history, the pope of Rome was originally one of the patriarchs of the Rome Empire, with that of Constantinople, Damascus, Alexandria, etc. But it is the only patriarch in the western part. Then in 5th Century A.D., Rome was totally destroyed by Goth. This brought in the time of barbarian invasions to the western Europe, especially the one of Lombard tribes into North Italy. Byzantine army was not able to defend Italy, so the Pope established the alliance with the King of Frank by crowning him as the Emperor of the Holy Rome Empire.

Not very long after that, Lombard was assimilated into Italians, and established the city states in Northern Italy. However, the dispute between Pope and Emperor became more and more severe. And for Lombards, it would be the only hope to be affiliate with Pope if they wanted to secure the freedom of their cities from the Emperor. This caused the Thirty-Year Wars, and Pope side became the ultimate winner. As an offshoot, the papal power reached its zenith.

Second, the persecution towards heretical thoughts at least before 12th Century was not quite severe. People can write their books, and put them into public discussions in order to find the unorthodox portions and recanted them.

Third, the Islam at origin was not quite religious. On the new area they conquered, Muslims didn't oblige other people to become Mohammedans. And those populace can live with peace by submitting a special tribute, which was much less than the tax of the Byzantine Empire. So not only Jews but Christians, especially Arians and Nestorians, welcomed their coming.

Before the reconquering of Spain by Christians, Muslims were quite confident about their religion, and showed their tolerance and appreciation towards secular knowledges, including Persian art and poetry, Greek philosophy and science, Babylonian astrology and alchemy, Indian mathematics and number system, etc. They translated those works into Arabic, and maintained them in colleges and libraries.

Thus, in later time, i.e. 12th Century, when western Europe revived from barbarianism, the scholars started to translate philosophical works from Greek and Arabic into Latin. There were three centers of this translating work -- Constantinople, Palermo, and Toledo. Among them, Toledo in Spain was the most productive one. And since Spain at the time was part of Arab Empire, this work was certainly done by Arabic scholars. In fact, they even established a sort of specific schools doing this job.

So finally, Russell stressed that this era was the fallen time for Western Europe, before which the splendor of Rome Empire and after which the Renaissance. However, both the Arab Empire and Byzantine Empire (i.e. Eastern Empire) conserved the civilization of ancient Greece and Rome, which was transmitted back to Western Europe to be the resource of the resuscitation of civilization. And in a larger sight, China at that time was approximately the Tang and Song Dynasties, which was the zenith of Chinese civilization. And Arab Empire was flourished itself. So the whole world was not that dark actually.

The tragedy is that during the 13th Century, both China and Arab were conquered and destroyed by Mongolian army, leaving Western Europe and Byzantine survived. Arab hasn't recovered from it until now. China was recovered partly, but was not flourished until the communication with western priests in late 16th Century and early 17th Century. This gave the chance for Western Europe to lead the world, and they really achieved.      

Reading A History of Western Philosophy

This July, I plan to finish the book "A History of Western Philosophy" written by Bertrand Rossell. Actually, I've been reading it for almost 3 years. However, hitherto I'm just at half of the book, which is the 10th Century in the medieval world.

During my reading time, I'll try to write some short comments, in order to remind me of some crucial points, and practice my English writing.

Comments on Aristotle's Logic

Since all the other parts of Aristotle’s logic theory have been proved invalid,
I will only focus on the theory of syllogism.

To illustrate the inherent formal errors within Aristotle’s system, Russell
gives an invalid inference of “Every golden mountain is mountain” + “Golden
mountains are gold” → “Some mountains are gold”. He says that since there
cannot exist any golden mountain, then the conclusion is false even if both the
major and minor premises are true.

However, from my point of view, the major premise cannot be true if there
doesn’t exist any golden mountain. Otherwise, then the conclusion should also
be true. I know that this is based on the induction instead of deduction. But I
don’t think this is a formal error in Aristotle’s syllogism system.

Comments on Aristotle's Physics

Russell has stated that the first part of Aristotle’s work has been refuted by
Newton’s First Law of Motion. Outside causes are required, not to account for
motion, bu to account for change of motion, either in velocity or in direction.
And circular motion involves a continual change in the direction of motion, and
therefore requires a force directed towards the center of the circle, as in Newton’s
law of gravitation.

His second part has also been refuted by astronomy observations and theories.
All the stars, including the Sun and the Moon, were born from nebulas, and will explode, or die of cold, which is neither ungenerated nor indestructible.

Cg vs GLSL

The Cg Tutorial    by Randima Fernando and Mark J. Kilgard

Some Basic Installation Things about Java

1. Set JAVA alternative:

sudo update-alternatives --config java

2. Set the environment variables for Java:

2.1 type the command:  sudo vim /etc/profile

2.2 Then at the end of the "profile" document, type the following:

#set java environment
export JAVA_HOME=/usr/lib/jvm/java-7-sun

export JRE_HOME=/usr/lib/jvm/java-7-sun/jre

export CLASSPATH=.:$JAVA_HOME/lib:$JRE_HOME/lib:$CLASSPATH

export PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH

2.3 Save the file. And type the following command to apply it immediately:
                        source /etc/profile

使用Eclipse的几个必须掌握的快捷键 + 改默认编码

转自：http://doggou.iteye.com/blog/211741

eclipse修改默认编码位置:菜单window->preferences->general->workspace->text file encoding

“工若善其事，必先利其器”，感谢Eclipse，她 使我们阅读一个大工程的代码更加容易，在阅读的过程中，我发现掌握几个Eclipse的快捷键会使阅读体验更加流畅，写出来与诸君分享，欢迎补充.


1. Ctrl+左键
这个是大多数人经常用到的，用来查看变量、方法、类的定义

2. Ctrl+O
查看一个类的纲要，列出其方法和成员变量。提示 ：再多按一次Ctrl+O ，可以列出该类继承的方法和变量。
助记 ："O"--->"Outline"--->"纲要"

3. Ctrl+T
查看一个类的继承关系树，是自顶向下的，再多按一次Ctrl+T, 会换成自底向上的显示结构。
提示 ：选中一个方法名，按Ctrl+T，可以查看到有这个同名方法的父类、子类、接口。
助记 ："T"------->"Tree"----->"层次树"

4.Alt+左右方向键
我们经常会遇到看代码时Ctrl+左键，层层跟踪，然后迷失在代码中的情况，这时只需要按“Alt+左方向键”就可以退回到上次阅读的位置，同理，按“Alt+右方向键”会前进到刚才退回的阅读位置，就像浏览器的前进和后退按钮一样。

5.Ctrl+Alt+H
如果你想知道一个类的方法到底被那些其他的类调用，那么请选中这个方法名，然后按“Ctrl+Alt+H”，Eclipse就会显示出这个方法被哪些方法调用，最终产生一个调用关系树。



Ctrl+D: 删除当前行 


Ctrl+Alt+↓ 复制当前行到下一行(复制增加)
Ctrl+Alt+↑ 复制当前行到上一行(复制增加)
Alt+↓ 当前行和下面一行交互位置(特别实用,可以省去先剪切,再粘贴了)
Alt+↑   当前行和上面一行交互位置(同上)
Alt+← 前一个编辑的页面
Alt+→ 下一个编辑的页面(当然是针对上面那条来说了)
Alt+Enter 显示当前选择资源(工程,or 文件 or文件)的属性
Shift+Enter 在当前行的下一行插入空行(这时鼠标可以在当前行的任一位置,不一定是最后)
Shift+Ctrl+Enter 在当前行插入空行(原理同上条)
Ctrl+Q   定位到最后编辑的地方
Ctrl+L 定位在某行 (对于程序超过100的人就有福音了)
Ctrl+M 最大化当前的Edit或View (再按则反之)
Ctrl+/   注释当前行,再按则取消注释
Ctrl+O   快速显示 OutLine
Ctrl+T   快速显示当前类的继承结构
Ctrl+W 关闭当前Editer
Ctrl+K   参照选中的Word快速定位到下一个
Ctrl+E 快速显示当前Editer的下拉列表(如果当前页面没有显示的用黑体表示)
Ctrl+/(小键盘) 折叠当前类中的所有代码
Ctrl+×(小键盘) 展开当前类中的所有代码
Ctrl+Space 代码助手完成一些代码的插入(但一般和输入法有冲突,可以修改输入法的热键,也可以暂用Alt+/来代替)
Ctrl+Shift+E 显示管理当前打开的所有的View的管理器(可以选择关闭,激活等操作)
Ctrl+J 正向增量查找(按下Ctrl+J后,你所输入的每个字母编辑器都提供快速匹配定位到某个单词,如果没有,则在stutes line中显示没有找到了,查一个单词时,特别实用,这个功能Idea两年前就有了)
Ctrl+Shift+J 反向增量查找(和上条相同,只不过是从后往前查)
Ctrl+Shift+F4 关闭所有打开的Editer
Ctrl+Shift+X   把当前选中的文本全部变味小写
Ctrl+Shift+Y   把当前选中的文本全部变为小写
Ctrl+Shift+F 格式化当前代码
Ctrl+Shift+P 定位到对于的匹配符(譬如{}) (从前面定位后面时,光标要在匹配符里面,后面到前面,则反之)
下面的快捷键是重构里面常用的,本人就自己喜欢且常用的整理一下(注:一般重构的快捷键都是Alt+Shift开头的了)
Alt+Shift+R 重命名 (是我自己最爱用的一个了,尤其是变量和类的Rename,比手工方法能节省很多劳动力)
Alt+Shift+M 抽取方法 (这是重构里面最常用的方法之一了,尤其是对一大堆泥团代码有用)
Alt+Shift+C 修改函数结构(比较实用,有N个函数调用了这个方法,修改一次搞定)
Alt+Shift+L 抽取本地变量( 可以直接把一些魔法数字和字符串抽取成一个变量,尤其是多处调用的时候)
Alt+Shift+F 把Class中的local变量变为field变量 (比较实用的功能)
Alt+Shift+I 合并变量(可能这样说有点不妥Inline)
Alt+Shift+V 移动函数和变量(不怎么常用)
Alt+Shift+Z 重构的后悔药(Undo)
Ctrl+Shift+U 选择选中的文字后非常类似于UE的列表查询
Ctrl+Alt+H 查看一个函数被其他函数调用的关系层次