java ，为什么无法从静态上下文中引用非静态方法?

Question

public class TextLinearSearch{    int[] list={1,4,2,5,-3,6,2};    public static void main(String args[]){   linearSearch(list,-3);   }    private void linearSearch(int[] list,int key){     for(int i=0;i<list.length;i++){    if(key==list[i]) System.out.println(i); }    System.out.println("There is no right number in the list");   }}